Owner’s Review: the Sinn EZM 7

Here’s the scenario: you’re on the third floor of a burning building, kitted out in all your firefighter gear, battling the blaze and smoke as you search for survivors. As you fight your way from room to room, the wood floors are buckling beneath your boots, and desperate sirens are blaring outside. In the intense heat, you have no way of knowing how long your equipment will last. Unless that is, you’ve added a Sinn EZM “Mission Timer” 7 to your loadout. 

Okay, I digress—I have never been in a burning building (knock on wood) and I hope I’ll never have to monitor the degradation of my “gear”, whatever that may mean. But I do have an EZM 7, and it has, surprisingly, come in handy in much more mundane situations than it was meant to be used in. 

To start at the beginning of my journey with the EZM (acronym derived from the German Einsatzeitmesser, or “operation time meter”), you may need a brief overview of the person writing this. Most of my friends and family would admit to having asked me to fix something on their car or in their home at some point, and to say that I’m into tool-style watches would be a devastating understatement. The more information that can be gleaned from (or tortured out of) a watch, the more likely I am to wear it. The EZM 7, then, is an easy win for me, and clearly my dad thought the same when he gifted me a used model upon the completion of my Master’s degree in Creative Writing in May 2024. 

Since then, the EZM 7 has usurped a good few of my watches to enter the “most-worn” pantheon. It shares the top spot with my beloved Seiko SNA411 Flightmaster, which had held the premier daily driver title for a whopping five years straight, a surefire endorsement of the hardy Sinn. On looks alone, they’re similar watches—both are incredibly visually “busy” and decently chunky. I also have them both on leather straps—a personal preference in strap material that I’ve tried to shake, but keep coming back to. They start to deviate from there, though, and over the past few months, the EZM 7 has given the tried-and-true Flighty a good run for its money as my go-to watch.

What’s In A Name: EZM 7 Basics

Let’s start with the EZM 7’s basic dimensions. Not a particularly dainty timepiece, the stainless steel, bead-blasted case clocks in at a respectable 43mm in diameter. At 12mm thick, it wears comfortably, but not lightly—you won’t find yourself forgetting that you have a watch on your wrist. The 22mm lug width makes strap-swapping relatively easy, and I traded the (admittedly durable) included silicone strap for a Sinn black leather piece with stitched red details. The first thing a seasoned watch enthusiast may notice upon picking up an EZM 7, though, is the “left-hand drive” screw-down crown. As a right-handed person, I was initially nervous that the crown would dig into the meat of my wrist, but I’ve yet to experience a single moment of discomfort at the expense of the Sinn’s crown. 

The bead-blasted element of the case isn’t for show, of course—it also totes Sinn’s TEGIMENT technology, making it completely scratch-resistant. I drop, fling, and bash this watch on everything I own with alarming frequency, and I can vouch that my EZM 7 looks as clean as it did the day I received it. For extra protective measures, it additionally features Ar-dehumidifying technology and a drying capsule indicator to prevent fogging and humidification, magnetic field protection up to 80,000 A/m, anti-reflective sapphire crystal glass, pressure resistance up to 20 bar (which is equivalent to 200m water depth), and a clockwise-ratcheting captive bezel. To further its indestructible cred, the EZM 7 is also reliably functional from -45 to 80 degrees Celsius (that’s -49 to 176 degrees Fahrenheit for us Yanks). Several more tough-as-nails features can be found on Sinn’s website, but the bottom line is that this thing could probably be thrown into Mt. Doom and make it back unscathed. 

A Guide to EZM 7 Color-Coding

Armed with such features, it’s clear that the EZM 7 is up to the heavy-duty firefighting tasks that it was made for. But if you’ve been playing along, you’re probably wondering why the hell the dial and bezel are so colorful; I know I had that same question when I first laid eyes on mine. The answer is unsurprisingly practical—each colored section represents the safe operation time of a particular piece of a German firefighter’s standard kit, hence the “Mission Timer” moniker. The categories are as follows: yellow is PA, or compressed breathing apparatus; yellow/green is CSA, or chemical protective suit; red is LPA, or extended time compressed air breathing apparatus; and green is DEKON II, or standard decontamination. 

These color-coded sections, paired with the stark white indices and hands, are a breeze to read at a glance against the matte black dial, which is vitally important for a first responder at the scene of a crisis—or for a work-from-home writer with poor eyesight and a touch of attention-deficit disorder. I’ll admit, the color-coded details are mostly eye candy for me, as I’m not using any auxiliary breathing apparatuses on a day-to-day basis. But the colored segments’ placements on the bezel can help with basic household tasks, too, if you’re so inclined. For instance, setting the bezel to the current position of the minute hand can help you visualize how much time has elapsed in your exercise routine, or how long you have before your laundry load finishes up. Not nearly as exciting as a daring rescue operation, but still a nice feature to have, which effectively serves as a bezel timer replacement. 

Final Verdict: A Pop of Color and Versatility

The EZM 7 does have a few catches, though. The power reserve is not stellar, meaning a day or two on the dresser will require setting the watch again (it runs on a Sellita SW-330, which features a second time zone via a 24 hour hand, making this watch useful for travel or simply tracking a time in another location). Since there is a date window, this may be annoying for those with a bug collection. Furthermore, its size and weight don’t make it very comfortable as a summer watch, or for those with smaller wrists. Still, if you’re in the market for a “hot” timepiece that brings charming character (and surprising everyday versatility) to the otherwise utilitarian category of tool watches, the EZM 7 may be the choice for you. Practice your German pronunciation and test those fire alarms, and I’m sure you’ll find something to love with the EZM 7, just as I did. 

As a final testament to the cool factor of the EZM 7, just weeks after gifting one to me, my dad bought one for himself. Whether we are the only father-daughter duo rocking this particular quirky Sinn remains to be seen, of course. 

The Sinn EZM “Mission Timer” 7 is available for around $2,000-3,000, depending on the vendor and new/used condition. Sinn