Amazon.com: Wheel Woolies Caliper Spoke Brush 18 in. Wheel Woolies Detail Brush 18" Large Medium Small Red Black Premium G Kefa Wheel Woolies Spoke Woolies Caliper Brush 18" Ahifi.sk Wheel Woolies Caliper Brushes Wheel Woolies Wheel Brushes By Braun Automotive. Wheel Woolies 18" Caliper Brush with red grip handle The Caliper Spoke Woolie is very similar to the original Wheel Woolie, except it has an angled head. Like the Wheel Woolie, the head is constructed of polypropylene fibers that reduce splatter. The Caliper Spoke Woolie is a great product for gaining access to the back of your wheel's spokes, in addition to a variety of other similar places that you might sometimes have a problem reaching. Description Caliper Spoke Woolie head is constructed of polypropylene fibers The head sits at a 45 degree angle Available in 2 brush sizes: 12 (1 1 2" OD) and 18 (1 3 4"OD) Metal free Chemical resistant