Topeak MTX Dual Sided Rack Frame attaches to Topeak MTX BeamRack series racks in seconds to provide stability for use with panniers. Features: Tough AL-6061 T-6 aluminum construction Attaches to Topeak MTX BeamRack series in seconds Perfect for using Topeak MTX trunk bag with panniers Includes left and right frame pieces. Rack sold separately Specifications: Weight Limit (lbs): 20lbs Tube Diameter: 6.4mm Seatpost Diameter: 25.4-31.8mm Weight: 300g Platform Dimensions: 11.6 x 0.8 x 12" Material: Aluminum