Whether you're warming up or winding down, move freely with BackBeat FIT 500 Series wireless sport headphones. Enjoy deep, rich sound, sweat-resistant nano-coating by P2i and a lightweight design for comfortable wearing all day. Listen more, charge less From the locker room to the lecture hall, you're always on the move. Listen for up to 18 hours on a single charge, then use DeepSleep mode to conserve power when your headphones aren't in use. Can't find a place to recharge? Listen uninterrupted with the 3.5 mm backup jack. Sweat it out Constantly on the move? P2i military-grade nano-coating protects the headphones against sweat, moisture and spills, so they're durable enough to withstand rainy commutes and gym sessions. SWEAT AND MOISTURE PROTECTION Sweat-resistant protection from P2i military-grade nano-coating 18 HR POWER Up to 18 hours of wireless listening and talk time on a single charge ON EAR CONTROLS Easy-access on-ear controls for calls and music HIGH QUALITY AUDIO 40 mm drivers and advanced acoustic technology provide deep, rich sound Bring your music to life Don't just hear your favorite tracks, feel them. 40 mm drivers and advanced acoustic technology deliver audio balance and deep, rich sound - whether you're hitting the weights or the books.