Small enough to fit in your dash but large enough to make your subwoofer bump. The KTA-200M is a tiny monoblock amplifier that will easily screw onto the back of select Alpine head units, allowing you to easily power a subwoofer. Packed with 400W x 1 DDP at 4 Ohms, it will give you the power you need for a add on subwoofer. Compatiable with Alpine's ilX-407 and iLX-W650. Included is the optional Alpine RUX-Knob, remote bass knob.