New in box - Power supply included. The portable Kala Tweed Amp is great for practice or jamming anywhere. Weighing less than five pounds, take it outside and power it with two 9v batteries or, for indoor sessions, plug into an outlet with the included AC adapter. This five watt amp has a five inch speaker and controls for volume, treble, and bass to dial in the perfect tone. Plug your headphones into the included jack for quiet practice or play along with your favorite songs using the auxiliary input for a phone or MP3 player. Play wherever the music takes you with the Kala Tweed Amp.