PSWI225 Polk Wireless Subwoofer (Black) Floor firing wireless powered subwoofer Compact ported enclosure features a rugged long-throw dynamic balance co-polymer driver with butyl rubber surround 2.4-gigahertz wireless transmitter Built-in subwoofer power amp with active crossover for accurate bass Powerful 100 watt amplifier features adjustable low-pass crossover, phase switch and subwoofer volume control