Pack of ten hard-coated replacement outside cover lenses (part number 777000) to suit the 3M™ Speedglas™ Welding Helmet Series 100. Hard-coated outside protection plates have a heavy-duty coating which helps prevent scratches, wear and tear. Hard-coated Speedglas™ cover lenses last approximately twice as long as the standard outside cover lenses. It is suggested to replace hard-coated cover lenses once a fortnight depending on use. The lens dimensions are 145 x 86mm.