SureFire Black EP4 Plus-Medium EarPro Sonic Defenders Hearing Protection Earpieces 1 Pair Medium EP4-BK-MPR 24dB* Noise Reduction Rating (NRR) with stoppers inserted Lowers potentially dangerous noise levels above 85dB Hear safe sound levels (with stoppers out) as if you weren't wearing ear plugs Ergonomic design and triple-flange stem design conforms to ear shape for comfort and secure retention Low-profile design allows you to keep them in place while wearing a mask, helmet, hat, or while using phone, headphones, or supplemental hearing muffs