The Fathom FKM rubber strap with folding clasp for Seamaster-style cases

FKM rubber with a folding clasp

The Fathom is a two-piece strap in FKM, a dense fluoro rubber that stays soft on the wrist and holds its shape. The top has a fine canvas-like texture and the underside has a zigzag pattern. The long piece ends in a pointed tip with a row of holes. The short piece carries a stainless steel folding clasp, so the strap closes the way a bracelet does instead of with a buckle you thread every morning.

Every Fathom comes with the silver folding clasp already fitted, and both pieces have quick-release spring bars at the watch end. Pick a color and a width and you have everything you need to wear it.

There are eight colors. Black has a thin white line along each edge, and All Black is black on black, the quietest of the set. Blue, Green, Orange and Red are the colors you see on dive watch dials and bezels, each with the same white edge line. White is the bright summer strap, and Brown is the warm one for a cream or gilt dial. For other bands made to fit specific watches, browse bands by watch brand.

Which width to pick

Width is the gap between the lugs of your watch, where the strap meets the case. Pick the width that matches your lugs exactly: a strap that is too narrow leaves gaps and shifts around, and one that is too wide won't go in. The Fathom comes in 18, 20, 21, 22 and 24 mm.

For Omega watches, these are the usual widths:

• 20 mm: Seamaster Diver 300M with the 42 mm case, and the Speedmaster Professional Moonwatch (42 mm).
• 21 mm: Seamaster 300 (41 mm) and Seamaster Planet Ocean 600M (43.5 mm).
• 22 mm: Seamaster Planet Ocean 600M (45.5 mm).

The other widths cover other watches: 18 mm for smaller cases, 24 mm for large divers. Any watch with standard spring bars at the right width takes the Fathom, whatever the brand.

The ends are straight. On a watch whose bracelet has curved end pieces that hug the case, a straight strap leaves a small gap between the strap end and the case. That's normal and doesn't change how the strap wears. If you're not sure of your width, our fit guide shows how to measure between the lugs.

Fitting and sizing

You don't need tools to swap it. Each end has a quick-release spring bar with a small lever on the underside. To take your old strap off, pull the lever toward the center of the strap and lift the end out of the lugs. To fit the Fathom, set one tip of the spring bar into its lug hole, pull the lever, line up the other tip with the opposite hole and let go. Give each end a gentle tug to make sure it's seated.

To set the length, open the clasp, press its pin through the hole that fits your wrist and fold the clasp shut. You only do this once: after that, you open and close the folding clasp to put the watch on and take it off, and the pin stays where you set it. A good fit keeps the watch on top of your wrist without sliding around and leaves room to slide a finger under the strap. If your wrist swells on a hot day, move the pin out by one hole.

Care

FKM rubber rinses clean. After the sea, a pool or a workout, hold the strap under fresh water and pat it dry with a soft cloth, clasp included. For dirt in the texture, use a drop of mild soap and a soft toothbrush, then rinse. Let it dry fully before you put it away in a drawer or a watch box.

Delivery and returns

Delivery is $6.95, or free on orders over $49. The delivery time for your country shows on each product page and at checkout.

You can return an unworn band in its original packaging within 30 days of delivery. Return shipping is paid by you, unless the item arrived faulty or incorrect. The full terms are on our delivery and returns page.