Buybits Ultimate Addons Adaptor Plate 3 Prong to RAM 1" Ball for RAM Motorcycle Mounts Custom made adaptor which incorporates the RAM 1" (25mm) ball fitting allowing our Ultimate Addons range of waterproof cases & holders to be used with a RAM motorcycle mount. If you already have a RAM motorcycle mount on your bike and would like to try one of our waterproof cases - you can. This simple adaptor turns our 3 lugg system to a 1" ball fitting which attaches directly on to any of the RAM arms. Suitable for use with the arms : RAM-B-201 / RAM-B-201A / Ram-B-201C. Note: Arms NOT supplied Adaptor plate only - NOT a complete mount