14,000 strokes per minute; .007" stroke length (.018 mm); precision removal resulting in less risk of gouging delicate parts; less aggressive than a Die Grinder; Lightweight & Faster than hand-filing. Only one wrench required; easier to change files; Easy grip rubber sleeve; Includes 1/8" collet insert. Accepts 1/16", 3/32", 3 mm collet inserts (sold separately). Lubrication is not recommended during operation. Lubrication is ONLY recommended during storage.