... temperature resistance 4)clear solar concentrator glass lens(GT-D22-10-1)1)material: optical glass(borosilicate),K9,BK7,B2702) light transmittance: ... optical glass, strictly perform ROHS environmental standard6) application range: suitable for big angle spotlight ,cars light,outdoor illumination,stree lamp,flashlight ... instrument,astronomical instrument. solar concentrator glass lens(GT-D22-10-1)