Studio Underd0g has built its reputation on a simple refusal: it will not make a boring chronograph. The British microbrand arrived with playful dials, direct-to-collector drops, and a sense that mechanical watches should be enjoyed rather than archived. The Mantis, reference 02MAHE_G2_M, continues that idea with a green dial that looks like it was pulled from a coral reef and dropped into a 02-series case. It is a watch that makes a first impression before you even check the movement.

That movement matters, though. The Mantis is not just a colorway exercise. It is a hand-wound chronograph with a Sellita heartbeat, a vintage-leaning case profile, and a strap-first wearing experience. It sits in the sweet spot between microbrand enthusiasm and real collector credibility. The question is whether the Mantis is more than a clever release. On the wrist, it reads as a serious little chrono with a sense of humor, which is a harder balance to strike than it sounds.

This review is written for the collector who already knows the difference between a spec sheet and a watch. We will cover the design, the movement, the ownership experience, and the value case. Where Studio Underd0g does not publish a confirmed figure for this exact reference, we leave it out rather than guess. The Mantis earns attention because of what it does on the wrist, not because it wins a numbers contest.

Brand context: from Kickstarter mischief to collector credibility

Studio Underd0g was founded in the United Kingdom in 2020 by Richard Benc. The brand's early story is a familiar one for modern microbrands: a direct-to-consumer model, a strong visual identity, and a community that formed around the drops. What made Studio Underd0g stand out was not just the price access point. It was the sense that the watches were designed by someone who actually enjoyed watches, rather than someone trying to fill a catalog gap.

The Watermelon chronograph became the calling card, and the brand's subsequent releases leaned into color, texture, and playful references. The 02-series represents a step up in maturity without sanding off the fun. The Mantis is part of that evolution. It keeps the color-forward DNA but places it in a more resolved package: a hand-wound chronograph with a known movement, a sapphire crystal, and a case that feels intended for daily wear.

That matters because microbrand credibility is fragile. A pretty dial can get you a first sale. A movement that can be serviced, a case that wears well, and a brand that communicates clearly get you a second sale. The Mantis is designed for the second sale. It is not trying to be a one-off novelty. It is trying to be the watch you reach for when you want something mechanical, colorful, and easy to live with.

Design and dial: the mantis shrimp in the room

The Mantis is named for the mantis shrimp, and the dial earns the reference. This is not a subtle olive or a safe forest green. It is a saturated, punchy green with enough depth to avoid looking flat under office lighting. The chronograph layout gives the dial structure, while the color keeps it from feeling like a classroom exercise in symmetry. It is the kind of watch that catches light and conversation in equal measure.

Studio Underd0g's design language is built on contrast. The Mantis uses that to good effect. The dial has a clear hierarchy, the chronograph registers are readable, and the hands are legible without turning the watch into a tool. It is not a lume-first sports chrono. It is a wearer's chronograph with a strong aesthetic point of view. That distinction matters. If you want a watch that disappears into a black turtleneck, this is not it. If you want a watch that gives a plain outfit a pulse, the Mantis delivers.

The case is stainless steel and the crystal is sapphire, which are the right choices for a watch at this level. The strap is leather, and the pin buckle keeps the package light and unobtrusive. The overall impression is vintage-leaning without being a costume. The Mantis does not pretend to be a 1960s racing chrono. It uses that language and then pushes it somewhere more contemporary. That is the Studio Underd0g trick: reference the past, but do not get stuck there.

The dial also rewards close looking. The green changes character with the light, moving from a rich emerald to something closer to a reef shadow. The chronograph subdials add visual texture without clutter. The result is a watch that feels designed rather than assembled. That is not always true at this price point. The Mantis has a coherent identity, and the color is the hook, not the whole story.

Movement: Sellita SW510 M, manual and honest

The Mantis uses a Sellita SW510 M hand-wound chronograph movement. This is a sensible choice for a small brand with a big design personality. Sellita movements are widely understood, widely serviced, and widely supported. They are not in-house exotica, and Studio Underd0g does not pretend otherwise. What you get is a known mechanical architecture with a chronograph function, a roughly sixty-hour power reserve, and a 28,800 vph beat rate.

The manual-winding experience is part of the charm. There is no rotor to hide the movement, and there is no automatic convenience to soften the ritual. You wind it, you set it, you wear it. The chronograph pushers add another layer of interaction. This is a watch that asks for a little attention, and that is a feature for the right buyer. It is also a reminder that mechanical watches are not appliances. They are small machines with habits.

The movement is not COSC certified, and the finishing is industrial rather than haute horlogerie. That is the correct trade-off at this price. A decorated in-house caliber would push the Mantis into a different category and likely a different price bracket. The Sellita keeps the watch accessible, serviceable, and honest. For a collector building a small, personal collection, that matters more than a fancy bridge or a signed rotor you will never see.

The power reserve is generous enough for a weekend off the wrist, though you should still expect to reset the time if you leave it longer. The chronograph function is the headline complication, and it suits the watch's playful character. This is not a rattrapante or a flyback. It is a straightforward chronograph done with a known movement and a clear purpose. That is enough.

Wrist feel and ownership

The Mantis wears like a vintage-leaning chronograph should: compact enough to slip under a cuff, but with enough dial presence to feel deliberate. The case sits close to the wrist and the strap does most of the comfort work. Studio Underd0g's leather straps tend to soften quickly, and the pin buckle keeps the package light and unobtrusive. It is the kind of watch you forget you are wearing until someone asks about the dial.

The watch is not trying to be a heavy tool watch. It feels balanced rather than dense, and the chronograph pushers are part of the daily ritual rather than an afterthought. If you like a watch that disappears during desk work and then pops when you roll up a sleeve, the Mantis is in the right zone. If you want a thick, armored chrono with a bracelet, look elsewhere. The Mantis is a wearer's watch, not a spec-sheet warrior.

Ownership is straightforward. The sapphire crystal means you do not have to baby the watch during normal daily wear. The stainless steel case is robust enough for regular use. The leather strap is the main consumable, and that is true of most dress-leaning chronographs. You can swap it for a different strap if you want to change the personality, but the green dial is always going to be the main event. This is not a watch that hides in a safe. It is a watch that wants to be worn.

The Mantis also has a useful social quality. It is a conversation starter without being obnoxious. The color is bold, but the case is restrained. That combination makes it easy to wear with a casual outfit, a smart jacket, or even a suit if you have the confidence to let the dial do the talking. It is not a formal watch in the traditional sense, but it can handle a dressed-up occasion with a knowing wink.

Accuracy and daily use

There is no COSC certification here, and that is fine. The Sellita SW510 M is a proven manual chronograph, and a healthy example should keep time within roughly ten to fifteen seconds a day in mixed wear, depending on regulation and how often you run the chronograph. It is not a quartz-beater, and it is not marketed as a precision instrument. Buy it for the mechanical experience and the dial, not for atomic timekeeping.

Daily use is where the Mantis makes sense. The hand-wound routine takes a few seconds in the morning, and the chronograph is there when you need it. The dial is legible, the case is comfortable, and the strap is easy to live with. It is not a watch for someone who wants to set it and forget it for months. It is a watch for someone who enjoys the small ritual of winding and checking. That is a different kind of ownership, and it suits the Mantis well.

If you are the kind of collector who rotates watches often, the power reserve gives you some breathing room. If you wear one watch every day, you will settle into a routine quickly. The chronograph function is not a gimmick, but it is also not the reason to buy the watch. The reason is the combination of color, case, and mechanical interaction. The Mantis is a watch that asks you to participate.

Occasions and wardrobe fit

The Mantis is at its best as a daily watch with a personality. It works with denim, knitwear, and casual tailoring. It can handle a dressier outfit if you lean into the green as a deliberate accent rather than a traditional neutral. It is not a black-tie watch, but it is not trying to be. It is a watch for the person who wants a mechanical object with a point of view.

For travel, the Mantis is a fun companion. It is easy to read, the chronograph can be useful for timing flights or parking meters, and the color makes it easy to spot in a bag. It is not a world-timer or a GMT, so it will not solve jet lag. But it will make the trip more enjoyable. For sport, it is not a dive watch or a rugged field watch. It is a chronograph with a leather strap. Treat it accordingly. For formal wear, it can work if the rest of the outfit is simple and the watch is allowed to be the focal point.

The Mantis is not a one-watch collection in the traditional sense. It is a watch that works best alongside a neutral daily driver or a proper dress watch. It is the fun watch, the weekend watch, the watch you wear when you want to feel like you are not taking the hobby too seriously. That is not a weakness. It is a role. Many collectors have a slot for exactly that kind of watch.

Value, investment, and the collector math

The Mantis sits in the accessible microbrand chronograph bracket. At its retail ask, it buys a hand-wound Swiss movement, a sapphire crystal, a stainless steel case, and a dial that looks like nothing else in the box. That is a fair value proposition for a collector who wants personality rather than a logo premium. It is not the cheapest mechanical chronograph you can buy, but it is not trying to be. The premium goes toward design, community, and the Studio Underd0g experience.

Investment value is a different conversation. Microbrand chronographs are not auction darlings, and the Mantis is unlikely to change that. The pre-owned market for Studio Underd0g tends to be stable rather than explosive. That means you should buy the Mantis because you want to wear it, not because you want to flip it. If you can get it at or near retail and you love the color, the value is there. If you are buying it as a financial instrument, you are buying the wrong watch.

The hold recommendation is simple: wear it, enjoy it, and do not underwrite your retirement with it. The Mantis is a color-forward microbrand chronograph with a known movement and a strong design identity. Those qualities make it a good watch. They do not make it a blue-chip asset. The collector math works best when the pleasure of ownership is part of the return.

Alternatives and homages

The Mantis does not have many direct rivals because few watches combine this level of color with a hand-wound chronograph movement at this price. The Baltic Tricompax is a natural alternative for buyers who want a vintage-inspired manual chronograph with a strong design language. The Lorier Gemini offers a compact, accessible mechanical chronograph with a similar collector-first attitude. The Seagull 1963 is the entry point for anyone who wants the hand-wound chronograph experience at a lower price, though it comes with a very different historical backdrop.

If you are looking for a more established benchmark, the Omega Speedmaster Professional is the aspirational reference. It is a completely different price category and a completely different ownership experience, but it shows what a manual-wind chronograph can become when it has decades of cultural weight behind it. The Mantis is not trying to compete with the Speedmaster. It is trying to offer a different kind of pleasure: color, personality, and a small-brand story you can wear on your wrist.

Homage watches are worth mentioning for collectors who want the look without the price. The Seagull 1963 is the classic entry-level hand-wound chronograph. The Dan Henry 1964 offers vintage chrono styling with easy everyday wear. The Sugess chronograph is another budget-friendly mechanical option. None of these watches have the Studio Underd0g design language or the Mantis green, but they can scratch the itch for a mechanical chronograph if the budget is tight.

Service and long-term care

Long-term ownership should be straightforward. The Sellita SW510 M is a known movement, and that means service is not a mystery. Studio Underd0g can service the watch, and a qualified independent watchmaker should be able to work on the movement as well. The sapphire crystal and stainless steel case are durable, and the leather strap is easy to replace. The main thing is to keep the watch dry and avoid exposing it to unnecessary shocks.

As with any mechanical chronograph, you should avoid running the chronograph continuously if you do not need it. Use the pushers properly, do not force them, and have the watch serviced if it starts to lose significant time or the chronograph function becomes sticky. The Mantis is not a fragile object, but it is a mechanical one. Treat it with the same respect you would give any hand-wound watch, and it should reward you with years of use.

Pros and cons

Final verdict

The Studio Underd0g Mantis is a confident, color-forward chronograph that understands its audience. It is not the most versatile watch in the box, but it is one of the most fun to strap on, and the hand-wound movement gives it a proper mechanical heartbeat. The green dial is the headline, but the Sellita movement and the comfortable case make it more than a novelty.

If you want a chronograph with a point of view, the Mantis has bite. It is a watch for collectors who value personality over polish and who understand that a mechanical watch is supposed to be enjoyed. Buy it because it makes you smile. That is the right reason, and for the Mantis, it is enough.