The SW118A-B is a single 18" subwoofer model designed to work in conjunction with an EJ2003-B or EL1503-B in applications where more bass is required. The SW118A includes an integrated 1000-watt class-D amplifier that includes onboard DSP. This amplifier is designed to power the passive SW118X when more than one unit are being used. Each unit is finished in heavy duty black Duracoat™. The SM118A is also available in white Duracoat™ finish, model SW118A-W.