Nixon Sentry Stainless Steel Watch. The Sentry is an elegant timepiece with an adventurous side. Think black tie meets block party. The face pops with depth and detail, but the solid stainless steel case, hardened mineral crystal, and waterproof rating of 100m, you don't have to worry about it not being able to hang in the real world. Hardened Mineral crystal material. Quartz movement. Stainless Steel band with Spring Bar connection. Imported.