E-A-R Classic Refill for One-Touch Dispenser. Refill containing 500 pairs, SNR = 28 dB, made of soft foam for excellent and comfortable protection. CE1 PU = 500 Pairs. The soft, energy-absorbing foam ensures low equilibrium pressure, making these earplugs one of 3M's most comfortable hearing protection products. They are moisture-resistant, meaning they do not swell easily due to moisture absorption. The proprietary, slow-recovery polymer foam ensures good acoustic properties. The cylindrical shape fits most ear canals and offers effective protection. The cellular surface structure prevents slipping, meaning the earplug does not need to be reinserted as frequently. They are compatible with the 3M E-A-Rfit Dual-Ear Validation System.