Whether you rock Fluences or EMGs, this universal battery pack from Fishman aims to replace the 9-volt batteries inside your guitar or bass. Wafer thin and smaller than a 2" square, the Fishman PRO-BPK-101 rechargeable lithium-ion power supply mounts easily inside many standard-sized instrument cavities. A quick 3-hour charge over USB, and the Fishman is primed to serve you weeks of play time (up to 200 hours; varies by load) without dropouts or brownouts. Its current capacity is comparable to that of a premium 9-volt alkaline battery, yet its size, weight, and convenience ensure you never find yourself at a gig or practice without juice. Live green and save green with the Fishman Fluence Universal Rechargeable Battery Pack.