Mica waveguide cover is a replacement part for your microwave oven. Made from heat resistant mica material, it shields the magnetron and internal components from steam, grease and food particles. If your microwave is sparking or arcing, a worn waveguide cover may be the cause. This replacement helps restore operation. To install, remove the old cover, retain original pins, clean the waveguide opening and insert the new mica plate. Verify your model number before ordering. Installation instructions not included.