This contact wheel assembly is 5/8" diameter x 3/8" width x 3/8" internal diameter. It includes the contact wheel and two bearings. This assembly ensures that your belt tools are kept running at maximum efficiency. Suitable for use with 11179, 11218, 11228, 11240, 11244, 11245, 11255, 11258, 11261, 11262, 11312, 11320, 11360, 11286, 11320, 15026, 11203, 11304, 11286, or a 11320 contact arm.