Barefoot International Boom Height AdjusterThe Height Adjuster is designed with quick release pins to make usage quick and easy. Simply pin the square end of the adjuster into the boom clamp just like you would the regular boom end. Then, insert the boom end into the desired hole on the adjuster to raise and lower the user end of the boom up to 12 either direction making the boom much easier to use for riders of various heights. Specifications Made from aircraft grade aluminum Only compatible