The rugged design of the Stinger safety glasses features rigid TPR flared temple ends, soft nose pieces, and properly placed ventilation ports to reduce fogging. With a single 9 base curve lens, it is designed for maximum impact resistance and superior side coverage. The BH691PFT also features a PFT lens.  Thanks to its chemical and physical properties, Performance Fog Technology is a permanent coating that prevents the formation of condensation on the lenses by absorbing the humidity drops.\nBH6G - Optional flame-resistant foam gasket for all Stinger styles. \nBH6FBG - Optional flame resistant foam brow gasket for all Stinger styles