This is a ButtKicker BKA-130-C power amplifier, a device that converts low-end audio frequencies into physical vibrations for immersive haptic feedback in gaming and home theater setups. It provides 90 watts RMS down to 2 ohms. The amplifier features controls for power, low filter cutoff (50 Hz - 70 Hz), and high cutoff frequency (70 Hz - 110 Hz). It is often used in simulation setups to simulate car engines, road textures, bumps, and curbs.

powers a single subwoofer very well. hook to the sub-out on your receiver. can use on a subwoofer that does not have its own amplifier asking 40 cash only