FEATURES Functions:CL Light, Stopwatch, Calendar Date,Dual Time Display, Week Date,Alarm(SIG/SNZ/ALM),Sound mode(MUTE/DST)Waterproof and Shock Resistant. Waterproof Level:3 Level,50M water resistant(Daily Use Waterproof, Hand Wash, Shower, Swimming, NO Problem. ) Wear Perimeter:13.5CM-20.5CM Battery Life: 3 Years MATERIALS Case Material: Plastic ABS757 Band Material: TPU thermoplastic elastomer rubber Mirror Surface: PMMA Back Cover:Stainless steel Buckle Material: 304 Stainless steel SPECIFICATIONS Product Length:9.25inch/23.5cm Product Weight:1.2oz/34g Dial Case Diameter: 1.7inch/43mm Dial Case Thickness:0.55inch/14mm Band Width:0.86inch/22mm Band Clasp Type: Buckle NOTIFICATIONS: Please DO NOT PULL OUT the Button Underwater. Use in extreme Hot or Cold temperature will shorter watch life. Clean the strap by a soft cloth on regular bases is highly recommended Too much water contact may shorter watch life Any quality problems just contact with us,we will reply to you with 24 hours