Increase volume with minimal drain on your game-caller battery. This 15-watt speaker system, with two internal amplifiers, puts sound out where you need it and has a game-finishing surround-sound effect. Selectable two- or four-speaker operation. Runs up to four hours at full volume on 16 AA batteries (not included) and adapts to any 12-volt power source. Works with any caller on the market when connected with a patch cord (not included).