HMILY&reg; Apple Watch Tempered Glass Ultra Clear Tempered Glass Screen Protector for iWatch Apple Watch (42MM) Specifically designed for Apple Watch. High Hardness Glass material after high tempered steel processing,surface hardness up to 8-9 h,impact resistance is strong,not easy scratches. Ultra-high light transmittance: (transmittance of 98% or more) optical transmittance grade, ultra-low reflection, high Transparency. 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. High quality antistatic adsorption film ,make the product bonding and separation simple,easy to operate. it will automatically bond the screen.