High-efficiency amplified speaker system. Active system with power control. Custom-designed neodymium micro drivers. 4 high-output aluminum cone speakers. 3.5mm input jack for all types of portable audio use. Compatible with ipod. Volume control. Operates on 4 x "aa" batteries (not included). Corporate, corporate gifts, executive, executive gifts, holiday gifts, recognition, recognition gift, name brand products, name brand, award, awards, business, business gift, gift accessories, incentive programs, catalog programs, fulfillment programs, recognition product, reward, rewards, thank you, motivate, year end gift, year end products, fall, christmas,inspire, bonus, electronic, electronics, video products, device, tv, promotional.