Clear View Filtration 412-480 Features:

The 4 in. Replacement Polycarbonate Sight Windows are made of 1/2 in. thick polycarbonate which also has a thin glass like AR2 (abrasion resistant) coating over both sides of the polycarbonate.This makes the window resistant to scratches, chemicals, solvents, and petroleum oils. These Windows can be cleaned using most all “common brands in. of brake clean. The thin glass coating may crack overtime because it does not flex or expand with heat at the same rate as the polycarbonate does. Windows should last for years of use but if a crack is visible in the window it should be changed. Sight windows are very easy to change and it is recommended you have a spare and Part #425 O-Ring Kit.