The A21 Automatic GMT has a naturally robust appearance, imparting a durable and tactical feel, matching that of its rugged specifications. The matte black dial adds a stealthy touch, while the bold and clear markings, in vintage sand colour SuperLuminova provide instant visibility.

Strap:Waxed Raw Edged Leather
Full Description

The 101-A21 Automatic GMT is meticulously crafted with the lineage of our renowned Holton Professional military issue model. Designed for precision and endurance, it features a robust shock protection system that ensures the reliability of it's GMT automatic movement even in the most demanding conditions.

Machined from solid 316L stainless steel, the case is vapour blasted with fine ceramic particles to create a matt pale grey, almost titanium colour who's appearance is both technical and beautiful to the touch.

In perfect contrast and framing the dial is a hardened steel bezel, with recessed 24h numerals topped with a bold 12h triangle, all flooded with vintage sand colour high grade SuperLuminova.

Under 2mm of toughened anti-reflective sapphire, lie four hands with bright matt white frames flooded with matching high grade 'lume' for perfect clarity.

The dual time GMT hand is perfect for travel and adventure with its bold arrow head, neatly missing the stubby hour hand to reference the 24h bezel for timekeeping in a second time zone.

Out of harms way at 4h lies the high grip crown, deeply recessed into the case and screwed down for protection against the hardest knocks.

Strap changes and personalisation are a cinch thanks to the fast release solid steel strap bars.

This no nonsense human powered automatic, is fit for purpose and ready for duty. It's no coincidence that it's technical specification reads like the ultimate watch kit check list.

The last two photos are stills taken from a video of a quartz Holton and a Kimmeridge strapped to an ROV in the Gulf of Mexico in March 2020, still working at 3900ft - almost 3/4 mile underwater.

As our way of saying thank you to serving and ex serving military and blue light personnel, we offer 20% military and 'blue light' discount on all our watches. Please email sales@elliotbrownwatches.com with proof of service and to find out more.




  • 43mm stainless case with matt gunmetal grey PVD coating
  • Ultra high grip, 120 click uni-directional bezel with case-hardened luminous insert
  • Scratch resistant 2mm sapphire crystal treated with internal anti-reflective coating
  • Superb night time performance with ultra bright X1 C3 Superluminova graphics
  • Japanese made Seiko NH34 automatic movement housed in EB's unique anti-shock system
  • 40 hour power reserve 
  • Solid stainless easy change screw in steel strap bars
  • Durable EPDM fitted rubber strap
  • Bolted down beautifully detailed caseback
  • Triple sealed, high grip screw down crown, recessed out of harm's way at 4h


-20/+40 seconds per day (manufacturer's figures)


  • 9H-3H 43mm excluding crown
  • 12H-6H - 52mm max to tip of case shoulders
  • Maximum thickness 14mm
  • Fits up to 190mm/7.5" wrist perfectly
  • Our leather and webbing straps fit larger wrists, and metal bracelets can have any number of links added 

Download the PDF here.

From the Journal

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