This durable design is consistent with the quality of the industry-trusted original Roto Brush. For use with a drill for rotation, this 5 ⅜" long brush head trains hair and wool and helps stimulate growth when used daily. It pulls up, separates and defines leg hair and wool as the first step in the fitting process. Long ball-tipped bristles stimulate the undercoat while short fiber bristles help fluff the longer top hairs for greater pop and bloom. Purple.