Replacement Ear Muff Pad Kit Includes Foam Inserts Replacement Ear Cushions Compatible with Grainger Part Number 21DE17 21DE22 475M53 52JH57 Cushion Material Foam Polyurethane PVC Noise Reduction Rating 27 dB Compatible with Manufacturer Model Number X4A X4P51E Compatible with Brand 3M PELTOR Dielectric No Compatible with Series X-Series X4 Standards CE Approved Cushion Color Black Electrically Insulated Yes Insert Color Black Insert Material Foam