The RAM-B-309-3U ball connects to the open hole on the side of the RAM-B-309-1U (single 1" ball) and is included with the purchase of the RAM-B-309-2U (double 1" ball). Note: The RAM-B-309-3U ball is for extension mounts to the RAM Chrome Motorcycle Brake/Clutch Reservoir Base
Material: Powder Coated Marine Grade Aluminum
Ball Size: 1" Rubber "B" Ball Size
Note: The "U" in the part number reflects product packaged in poly bag.