45 mm 1 8 1 8 icon-account icon-glass
Jack Mason Strat-o-timer Automatic GMT

Leading the Way In the GMT Revolution


Automatic GMT. Limited to 500.
  Available in 3 Colors

A new era.
Be the first.

Housing the all new and limited Miyota Caliber 9075 movement, the Strat-o-timer features an automatic GMT movement with jump hour functionality. Other features include a boxed sapphire crystal, 200m WR, and a bi-directional bezel with multi-colored SuperLuminova. This entire package is designed, assembled, and regulated in the USA.

Special Early-Bird Perks

Limited to the first 500 units reserved.

Automatic GMT

Strat-o-timer GMT in the color of your choice.

Straps Set

Special FKM and limited edition leather straps.

Matching Leather
Bag Tags

3 leather bag tags that match your Strat-o-timer GMT.

Digital print of
original sketch

Frame-ready, poster quality digital print of concept sketch.

Exclusive Strap

Get 20% off on all straps from now until the end of 2023.

First access to the
Seatrek 40

Get exclusive info and first access to our next launch.

Checks Every Box

The Strat-o-timer GMT checks every box. Loaded with top of the line specifications and completely designed at our studio in Texas, this watch was held to the highest of standards.


Miyota 9075

Movement Type
True GMT with Jump Hour


+/-5 seconds per day (regulated by Jack Mason)

Hours, Minutes, Running Second, GMT Hand, Date

Vibration Frequency
28,800 vph

Power Reserve
42 Hours

Custom branded rotor

Case & Dial

316L Stainless Steel


13mm (11.25mm excluding crystal)

Lug Width

Lug to Lug

Depth Rating
200m, 20 ATM


48-click, Sapphire with lume

Crystal Type
Double-domed, Boxed Sapphire

Swiss Super-LumiNova® BGW9, X1 C3

Display with sapphire


316L Stainless Steel

20mm > 16mm taper

On the fly micro-adjust

End Link
Solid with quick-release


Unique Features

Miyota Caliber 9075

Automatic GMT. The Miyota 9075 is a self-winding movement with a 42 hour power reserve, 24 jewels, and 28,800vph. Its functions include a GMT with jumping local hour, which is functionally identical to a Rolex GMT-Master II and is generally only reserved for watches in higher price ranges.

Regulated in the USA

Fine tuned for accuracy. Every Strat-o-timer GMT has been regulated for higher accuracy by Jack Mason. Like a car engine, we take a stock part and maximize its output for better performance. It is regulated to an accuracy of +/- 5 seconds per day. Without regulation, the movement’s stock accuracy is +30/-10 seconds per day.

Assembled in the USA

A first for Jack Mason. We are bringing watch assembly closer to home in order to have full ownership over quality control. This is another step closer to fulfilling our vision in establishing ourselves as a legacy brand that holds generational value.

True GMT vs Caller GMT

Jumping hour hand functionality. Both versions of a GMT have a fourth hand to display a second time zone. However, a True GMT allows for independent adjustment of the time without affecting the GMT hand (which a Caller GMT can’t do). This means a wearer can set the GMT hand to home time and then conveniently adjust the local hour hand while traveling.

Vintage Inspired Sapphire

Double domed, boxed sapphire crystal. The Strat-o-timer GMT sports a sapphire crystal that is raised above the bezel by a few millimeters as an homage to vintage watches that used acrylic crystals. We’ve recreated this look with a sapphire crystal in lieu of acrylic to increase the durability and reduce any potential scratching.

Read the Lume

Seven layers of Swiss Super-LumiNova®. To increase low-light legibility, Swiss Super-LumiNova® has been added along the bezel, dial, and hands. The bezel has 7 layers of printed lume and the indices are filled with lume for a deeper, longer lasting glow.

The Perfect Fit for All Wrists

On-the-fly bracelet adjustment. The 7-row, 316L stainless steel bracelet has a comfortable 20mm to 16mm taper and is equipped with solid, quick-release end links. The micro-adjust buckle seals the deal and ensures a great fit on wrists of all sizes.

Jack Mason Strat-o-timer Automatic GMT

In The Media

“A fresh GMT with an even fresher movement.”
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“The Strat-O-Timer GMT features an iconic design language, yet still feels novel enough to stand out from the crowd.”
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“The Strat-o-timer was designed to the highest of standards and checks off every box from a quality and specification standpoint that any enthusiast would crave.”
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“Assembled in the U.S., the watch marks new territory for the brand – and a prime opportunity for collectors.”
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An Impressive Entrance

Strat-o-timer GMT First Look Event. The prototypes were revealed at our studio in Dallas, Texas among a group of YouTubers and enthusiasts from the watch community. The excitement was high as the prototypes were passed around.

Watch Strat-o-timer Videos

Behind the Design

It Started With A Big Idea

Original 7 Foot Concept Sketch. A big idea takes center stage as designer Peter Cho creates a massive 84” concept sketch of the Strat-o-timer GMT. Now on display at our studio in Dallas, the original concept sketch will be available as a digital print for the first 500 pre-orders.

Design to Watch

A look behind the design. Designing a watch from start to finish is a process with multiple phases that often takes over a year. Our Design to Watch series follows the Jack Mason team through the process of materializing the Strat-o-timer GMT from concept to prototype. Watch along at each step of the process on our Youtube channel.

For You. From Us.

We couldn’t keep it to ourselves. Our small team of high caliber talent has worked to create a premium brand experience at every level. All creative content is produced in-house and is held to the same high standards that our products are held to.

Comments from the Community

“Looking forward to the Jack Mason true GMT watch!”
David B.
“I love the use of the miyota 9075, shows you guys actually know what you’re doing”
“The jumping hour hand is EVERYTHING”
Jack B.
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Jack Mason Strat-o-timer Automatic GMT

Strat-o-timer GMT