featureUnidirectional rotating bezel Small seconds date Helium escape valve Limited Edition (2,021) Master Chronometer Certified Screw-down crown Time zone function Transparent case back Unidirectional rotating bezel ?? caseTotal product weight (approx.):????135 gBetween lugs:????21 mmThickness:????16.1 mmCase:????Stainless steelCase diameter:????43.5 mmWater resistance:????60 bar (600 m/2000 ft)??Dial and CrystalDial color:????whiteMirror:????Arched wear-resistant sapphire crystal, double-sided anti-reflective treatment ?? braceletMaterial:????Rubber strapStrap color:????blueStrap bottom:????RubberClasp type:????Folding claspBuckle material:????stainless steel