TCP Global Brand 14 Piece Micro Air Grinder Kit With Case & All Accessories Pencil Type Micro Air Die Grinder features a variable speed throttle control for any speed up to 58000 rpm and has a self-closing lever. It's ideal for cleaning and polishing of jewelry, porting cyliner heads, dies or any hobby and craft uses. Includes 10 different styles of grinding stone bits,but the .112" collet allows this micro grinder to be used with a large variety of .112" Dremel tool bits. Has a extremely flexible 50" hose with an abrasion guard that allows you to reach the most difficult areas. It's slim, lightweight, durable and comfortable to hold and use