Nixon Sentry Leather Watch. The Sentry Leather is an elegant timepiece with an adventurous side. Think black tie meets block party. The face pops with depth and detail, but with the solid stainless steel case, hardened mineral crystal, and waterproof rating of 100 meter / 10 ATM, you don't have to worry about it not being able to hang in the real world. 42mm watch size. Stainless steel watch case with 12mm case thickness. Hardened mineral crystal material. Quartz movement. Leather band with spring bar connection. Free swing band type. Imported.