GGS II LCD Glass Screen Protector for Canon EOS 600D T3i It is rigid and made of optical glass material, which achieves more than 90% of transmittance (higher than plastic LCD screen protectors), thus making the LCD screen clear. Only 0.5mm thick with 6 layers of coatings and UV Protection. Optical glass strengthened through special crafting process. Prevent scratches, collisions and moderate impact to the LCD screen. The protector is reusable.