Cast special plastic (CR39), clear, temperature resistant up to approx. 140 °C. CR39 prevents metal spatter from sticking and thus remains transparent for much longer than conventional mineral glass or polycarbonate lenses. It is a thermosetting plastic, meaning the material does not melt but decomposes at temperatures above approx. 300 °C. Type Article Version Protective Equipment Features clear, temperature resistant Main color transparent Variation Cover Lens