The Caldwell E-MAX PRO Ear Muff 23NRR is high quality bluetooth hearing protection with an all day comfortable fit at an affordable price. It is compatible with mobile devices and the low-profile design allows for uninterrupted cheek weld. It also features high quality stereo sound with 23dB noise reduction rating and easy-to-use push button volume controls. 23dB NRR; High quality stereo sound Low-profile design for uninterrupted cheek weld - Compact folding design Easy to use push button volume controls; Illuminated on/off indicator; Auto-shutoff (4 hours without touching controls) Runs on 3 AAA Batteries (included) - Compatible with Caldwells Rechargeable Lithium-Ion Battery Pack (sold separately) Available in youth sizes and colors