The modular MB4 Panaray Subwoofer system from Bose offers extended low end for permanent and portable applications. You can set it up as a standalone unit or in a stacked array. With a frequency range of 40Hz-300Hz, 110dB SPL, and 200W power handling the MB4 Subwoofer delivers serious bottom end. 2 parallel NL4 connectors. Bose includes a 5-year transferable limited warranty with your Panaray Subwoofer.