Magnolia Brush truck exhaust stack cleaning brush. White tampico fiber staple set in a flexible circular plastic block, with standard thread handle hole. This brush was designed for cleaning chrome plated exhaust stacks on diesel trucks. Good for cleaning overhead pipes in food processing plants. 3-3/4-inches inside diameter. 9-inches overall diameter, 1-7/8-inches block width, 1-3/4-inches trim length.