GGS DSLR LCD Optical Glass Screen Protector for Nikon D40 / D40X cameras It is rigid and made of optical glass material, which achieves more than 90% of transmittance (high 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.