This flat glass is VYCOR®, and has been developed for its resistance to heat, thermal shock and chemical attack. It can be used at temperatures up to 1200C and is transparent to wavelengths from Ultraviolet to Infrared. Its main application is use as a sight glass. VYCOR® is three times more resistant to wear than other optical glasses. Electrical properties are similar to those of Fused Quartz. VYCOR® is more resistant to discoloration from exposure to radiation than other optical glasses.