Caliber BC108US 8-Inch Enclosed Active Underseat Car Stereo Subwoofer System – Black. Bring your music to life with the Caliber under seat amplified bass solution without losing valuable boot space. A solid die-cast enclosure houses both an 8 inch / 20cm subwoofer and a 100W RMS (500W peak power) integrated amplifier. Compact in size (350 x 235 x 70mm), the BC108US fits under most front passenger seats or neatly behind seats in a van/ truck, to give a powerful bass upgrade. Install the remote which is included so adjustments can be made in real time to suit listening tastes. You will require an amplifier wiring kit to install this product. Remote bass control included.