Petite earpieces are ideal for those with smaller ear canals. Soft polyurethane foam expands to fit snugly without creating uncomfortable pressure. Smooth, soil-resistant closed-cell foam skin helps keep plugs clean. Contoured T shape makes insertion and removal easy. Leight Source 500 Refill. Corded/Cordless Pair: Cordless; Shape: T; Material(s): Polyurethane Foam; Noise Reduction Rate (NRR): 30 dB.