When fitted, it will protect the wearer's face due to the special wrap-around design. It fits most standard safety helmets which have a 30 mm slot & are best used with KARAM Helmets. Easy to use in a variety of work situations. This Welding Shield is certified to be used only in conjunction with a safety helmet, and should not be used independently. IR 5 or IR 11 Lens can be inserted between two protective lens made of clear high impact resistant polycarbonate.