Description Pack of ten standard replacement 3M™ Speedglas™ outside cover lenses (part number 526000) to suit the Speedglas™ Welding Helmet Series 9100 and the Speedglas G5-01 Heavy Duty Welding Helmet. Outside cover plates protect the outside of your 3M Speedglas 9100 or Speedglas G5-01VC auto-darkening lens from sparks and splatter Outside protection plates are essential for the care and maintenance of your Speedglas welding helmet It is recommended to replace outside cover lenses once to twice a week depending on use Also available in either hard-coated (part number 527000) or high-heat (part number 527070) cover plates Cover plate dimensions 155 x 96mm.