Check the listing for details. Sound Town 21" Cast Aluminum Frame Woofer 1000W Low Frequency Driver STLF-21500A. Condition: New. Listed at 293.24 USD. Sound Town 21” 1000W Cast Aluminum Frame subwoofer (Low Frequency Driver), Replacement Woofer for super High-Power Subwoofer Cabinets (STLF-21500A)The Sound Town STLF-21500A comes with a 21” replacement driver for high power subwoofer cabinets; it is compatible with the Sound Town subwoofers and other brands which need a 21” high power subwoofer as well. The subwoofer comes with 8-ohm impedance and has a frequency range of 32-2K Hz. Sensitivity is 108dB. It is built in a cast aluminum chassis with 5” voice coil and 200 oz magnet. It has a paper cone with cloth edge. With 1000W RMS power handling capability, the STLF-21500A delivers massive and deep bass and makes a great replacement woofer for your 21-inch high power subwoofer cabinets.Features: 21” cast aluminum frame5” voice coil and 200-oz magnet produce superb bass sound1000W RMS power handling capabilityDimension and Weight: Shipping Dimension (in.): 23.8"W x 23.6"D x 11.6"H Shipping Weight (lb.): 48.4lbs