The MTC-210UB-WH optional U-Bracket accessory is designed for use with the JBL Professional Control SB210 subwoofer. The U-Bracket allows installation of the enclosure to flat sturdy surfaces, while enabling an axis of rotation. The MTC-210UB-WH is constructed of 10 Gauge Steel (0.134 in. thick), is zinc plated and finished in Polyester Based White Powder Coating.