ButtKicker Wireless Home Theater Kit, Includes ButtKicker Advance and Power Amplifier BKA300 (BK-KIT-4) Offers true infrasonic, or low-frequency response Attaches to seats and floors, and sends low-frequency sound directly into the listener's body Accurately reproduce the feeling range of many natural and man-made sounds Now with wider couch / chair mounting accessory kit BKA300-4 amplifier (115v) has integrated wireless option