Product Features: Hand-ground, bright matte surface. Quite bright even at f/8! Clarified glass for increased sharpness Size of ground glass is exactly 4"x5"x0.07"(inch) | 102x127x1.8(mm) blank The Focusing screen Size: 3.9"x4.9"x0.08"(inch) / 101X127x2.0mm with grid. It is made of optical glass,it is frosted and hardened, not fragile.ultra-thin and high-permeability,very delicate. Clear and high contrast, easy to focusing, more brighter than general ground glass 45 degree clipped corners. Matte ground surface is on one side of the glass, the other side is regular glass. The glass sides are smooth so there is no danger of accidental cut. Make sure to install the grounded surface on the inside of your camera in order to protect the grounded surface and not have a focus shift upon taking your shot with a film holder. Suitable for Universal focusing screen works for 4x5 large format camera, like Linhof, Wista, Toyo,Sinar, Chamonix,Horsemans, Sheng Hao, Tachihara etc. Package: 1x Ground Glass