High NRR plugs deliver superior noise-blocking performance. Contoured bell-shaped design provides an excellent ear-canal fit with enhanced back-out resistance. Soft, expanding polyurethane foam ensures a comfortable fit. Smooth, soil-resistant closed-cell foam skin protects against dirt buildup. Leight Source 500 Refill. Corded/Banded: No; Size Type: One Size Fits Most; Attenuation Rating: 33 dB; Reusable: No.