Infinity Reference Basslink II 250-Watt Dual 10-Inch Powered Subwoofer System (Black) 250-Watt powered subwoofer system with vertical or horizontal mounting to fit tight spaces Square 10-inch subwoofer and 10-inch passive radiator maximize cone area and provide more bass output from a smaller housing Expansion slot for optional 35 Watt x 4 system amplifier with phantom center channel control User-adjustable input sensitivity, crossover frequency and bass-boost to optimize for any installation Included remote bass level control; One-year warranty