Behringer VP1800S, 18"" Subwoofer, Power: 400 W RMS, 1600 W peak, Built-in speaker stand mount, 2 Speaker Twist sockets, Impedance: 8 Ohm, Frequency response: 40 Hz to 200 Hz, SPL: 100 dB (Half space, 1 W @ 1 m), Crossover frequency: 200 Hz recommended, Dimensions: 530 x 650 x 615 mm, Weight: 41.4 kg, Suitable protective cover: Article no. #495499# (not included)