Green 3D Full Glass Screen Protector 40mm for Apple Watch 3/4/5 This product is a full glass screen protector that is only 0.3mm thick and made with chemically strengthened tempered glass. It is a 9H hardness level which is 3 times stronger than regular PET film. The oleophobic coating helps resist fingerprints and other contaminants. The protector is case-friendly and fits for Apple Watch 3/4/5. It also comes with a lifetime warranty.