ToolUSA Cylindrical Felt Bobs Set. These bobs, with their cylindrical shape measuring 1/2" (1.3 cm) x 3/4" (1.9 cm), have been meticulously designed to polish both the interior and exterior surfaces of your workpiece, ensuring a smooth, lustrous finish. Jewelry designers and craft enthusiasts will appreciate the precision and efficiency these bobs offer. They are compatible with most rotary tools, offering a versatile solution to your polishing needs. The bobs come pre-mounted on a 3/32" (0.24 cm) shank, with an overall length of 1 5/8" (4.1 cm), providing stability during the polishing process. Each pack provides not one, but two sets of these cylindrical felt bobs, and with this offer, you'll receive three packs, summing up to a total of six pieces. This ensures that you have a generous supply at hand for extended projects or to share with fellow crafters. Whether you're an experienced jeweler or a hobbyist, the ToolUSA 2pc Cylindrical Felt Bobs Set is a must-have in your toolkit, promising precision and a polished finish.