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 Ultra-Violet 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.