The JBL Cinema SB450 Wireless Subwoofer is designed to enhance the sound quality of your JBL SB400 soundbar by providing deep bass and powerful audio output. This sleek black subwoofer in a cube shape is compatible with the JBL SB450 model and features Bluetooth connectivity for wireless audio streaming. With an RMS power of 200W and an impedance of 4 Ohms, it delivers immersive surround sound in 2.1 channel format. Perfect for improving your home audio experience, this subwoofer from JBL is a reliable and high-quality addition to your sound system. This subwoofer is a replacement subwoofer and only comes with the subwoofer and power cord and not the soundbar. It is tested and works great.