Description The 3051.GO.NSF was designed with the Navy Seal Foundation (NSF), and features the NSF logo on its case back. It is now available in a trendy tone on tone grey-out version, adorned with a monochrome Luminox logo on the dial.The 3050 series' design is captivating due to its pronounced "turtle shape". This watch is unique thanks to its protected crown and dive bezel. It is water-resistant up to 200 meters, thereby making it usable for diving as well.Its proven Luminox Light Technology lighting system provides self-powered readability in any situation. "Always Visible", for up to 25 years. More Details Origin: Swiss Made Always visible: Constant glow for up to 25 years Function: Time date Movement: Swiss quartz Caliber: RONDA 515 Water resistance: 200 meters / 660 feet / 20 ATM Case diameter: 44 mm Bezel: Unidirectional rotating Case material: CARBONOX™ Case back: 316L Stainless steel screw on Crystal / glass material: Hardened mineral crystal (550-650 Vickers) Crown: Security gaskets, crown protected Strap / bracelet: Black genuine rubber Strap / bracelet buckle: IP black 316L stainless steel Lug width: 23 mm Case height: 14 mm Weight: 64 g Approximate battery life span: 60 months