The Bass Traveler from M-Audio is a two-channel, rechargeable headphone amplifier capable of powering two sets of headphones, while ensuring crisp clear sound. The unit also features an integrated Boost switch, offering flat, medium, and high settings to optimize the sound for any headphones. The rechargeable lithium-polymer battery offers up to 8 hours of use from a single charge. The TRRS connections are compatible with most popular in-line remote control headphones. The Bass Traveler also ships with a TRRS connection cable and a micro-USB charging cable.