Overview These Black Bay inspired watches hark back to the classic military watches of the late 1950s. The watch has a screw-down crown, but the absence of crown guards gives the watch a sleeker, more elegant, vintage feel. Watch Specification Model:SD1958 Movement: Japan NH35 automatic, 41 hours of energy storage. Case material:316L stainless steel Case back: 316L stainless steel Bezel:120 Clickunidirect rotationalceramic bezel Watch mirror: sapphire crystalwith AR coating. Water resistance: 200 m / 20 ATM Luminous: Swiss BGW9 blue super luminous. Crown: Screw-Down Case back:Screwback Case Watch Dimension Case diameter:41.1mm(without crown) Case length: 49.7mm(lug to lug) Case thickness: 14.85mm Lug width: 22mm Our service Warranty: 2years Returns and Refund: 30 days return & refund service Package: watch,warranty card, user manual, plastic protecting box Style: mens mechanical watch, mens automatic watch, dive watch, luxury watch