The MTC-30UB(-WH) optional U-Bracket accessory is designed for use with the JBL Professional Control 30 and Control 31(BBY SKU#6465203). The U-Bracket allows installation of the enclosure to flat sturdy surfaces when the included InvisiBall Mounting Structure is not appropriate.The MTC-30UB is constructed of 11 Gauge Steel (0.12 in. thick), and is finished in Polyester Based, Black or White (-WH) Powder Coating. | Jbl | | Control 30 U-Bracket Accessory | White | Best Buy