This is a 8" Sunfire powered subwoofer. Dynamic Series. It has right and left out signal and right and left in signal. signal sensor and signal on. has volume max to 0 DB and minimum. Has phase zero 90 and 180. Has 50 hertz 100hz normal and 150 HZ bypass crossover frequencies. Power 100 to 120vac 50 to 80 HZ to amp AC input on and off switch with two 8-in speakers. This subwoofer usually retails for about $300. but there is literally zero on the market.