The B-II is crafted specifically for acoustic upright basses. On the inside, all new electronics deliver cleaner, more transparent sound and an unprecedented 400 hours of battery life. The preamps are housed in a rugged, lightweight injection-molded case, measuring 1.375" high x 3.5 wide x 5" long. Controls include input gain, treble, bass and volume. Input accepts all piezo and magnetic pickups, passive or active. These units come complete with rubber feet and a heavy-duty stainless-steel belt clip.