Tempered Glass Features: 100% brand new.Specifically designed for Apple Watch (38mm & 42mm).Metal edge full coverage, more perfect protection for Watch.High Hardness: Glass material after high tempered steel processing, surface hardness up to 8-9 H, impact resistance is strong, not easy scratchesUltra-high light transmittance: (transmittance of 98% or more) optical transmittance grade, ultra-low reflection, high transparency.High sensitivity: The glass is coated on the back with a strong silicon adhesive that makes installation easy and attaches the film firmly so as to not affect the touch screen's sensitivity.Automatic bonding: High quality antistatic adsorption film ,make the product bonding and separation simple, easy to operate. it will automatically bond the screen.Material: tempered glass + Aluminum-magnesium alloy.Compatible Models: Apple Watch 38mm/42mm Apple Watch Cover/Case Features Material: TPU RubberCut and opening for all portsNew design, more safe and fashionableSuitable for Apple Watch/ Apple Watch Sport/ Apple Watch EditionProtect your apple watch from Fingerprints, Scratches, Dusts, Collisions And Abrasion. Installation guide - This product is made by 9H tempered glass with curved surface, and it requires to CLEAN the phone screen surface very carefully. Please make sure the phone surface is free of any dust or lints as they will cause bubbles between glass and protector which can not be eliminated without removing and disposing the tempered glass protector.(Once the glass has been applied, it may not be removed and re-used as it will not adhere properly) Before installing the glass, please align the tempered glass protector perfectly to the phone as once the tempered glass has been applied to the phone surface, it may not be removed and re-used as it will not adhere properly. If is not aligned well, the glass will not adhere properly and touch sensitivity of the phone will be affected.