Ideal for motorcycle handlebars, the RAM-B-231ZU consists of a 1" B size rubber ball attached to a zinc-coated metal U-bolt base. Designed to sit at right angles to the mounting rail, the U-bolt base accommodates rails from .5" to 1" in diameter. Included are black cover caps to be placed over the exposed ends of the U-bolt as well as a composite adapter that can narrow the rail to a minimum width of .5".