Stem mounted 4” wire wheel brush with ¼” (6.35mm) hex shank is specifically manufactured for hassle-free access into narrow holes and tight, confined spaces. Effectively removes unsightly and damaging rust, scale and paint in hard to reach areas. Features a crimped style ideal for light to medium duty applications. Compatible with any ¼” (6.35mm) diameter electric power drill or 01990 pneumatic (air) drill. Product contains a 6, 000 maximum RPM.