The 3M 428000P05 Protective Shield Inside is a genuine 3M Speedglas inner cover plate designed to safeguard the welding filter from damaging sparks and spatter. Crafted from durable, clear polycarbonate, this essential spare part helps maintain optimal vision and extends the life of your welding lens. It is recommended to regularly inspect and replace the inner protection plate when it becomes deeply pitted, scratched, or too dirty to clean, ensuring continuous safety and performance for your welding helmet. This pack typically contains 5 replacement plates.