Deepwater Meridian 300 Titanium HEV Automatic 44mm HNBR Synthetic Rubber Strap Watch YGroup_MarlinJetAmerica25038mmFabricStrapWatch All polished finishing brings timeless elegance The Marlin Chatham Automatic All polished finishing brings timeless elegance to the 22mm case and stainless steel mesh band on this petite timepiece and a chronograph with a pulsometer that allows the center hand to be used in conjunction with the outer minute track to record or check your pulse rate in addition to regular timekeeping You’ll find an automatic helium escape valve positioned on the case beside 10 o’clock that allows for the release of trapped helium to prevent damage to the crystal during decompression and we’ve equipped this timepiece with a screw down crown and screw on case back