Howard Leight by Honeywell MAXIMUM Single-Use Earplugs, Leight Source 500 Refill, Cordless, 33NRR, Coral, 500 Pairs - 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.