Advanced technology merges with a comfortable design in the ISO Tunes Men’s Defy Slim Blue Tooth Ear Defenders to offer you hearing protection with a sound environmental awareness. Built with tactical sound control technology the ear defenders are effective in blocking impact noise while enhancing hearing. The lightweight rechargeable lithium-ion battery pack can be replaced with 2 x AAA batteries for receiving up to 300 hours of battery life. IPX4 sweat and water resistance confirms your hearing in any weather conditions., Tactical Sound Control / Level Dependency. Up to 300 hours use with 2 x AAA batteries., IPX4 sweat & water resistance. Bluetooth 5.0 and 30-foot range., 20 NRR / 27 SNR. SafeMax 85 dBa volume limit., ,