3M™ Speedglas™ Inside Protection Plate 9000X/XF is designed to help protect the inside surface of the filter from spark and spatter. Failure to use an inside protection plate with the filter voids the warranty if spark or spatter cause damage to the glass. 3M™ Speedglas™ Inside Protection Plate 04-0280-00/37135 is a replacement part for 3M™ Speedglas™ Filters 9100X.