AST218 Features: -56,000 RPM.-Collet Size: 1/8".-1/8" Pencil Type Die Grinder. Color/Finish: -Air pressure: 90-120 PSI Designed for high speed porting and finishing of small parts. Also designed for tight spots!. Dimensions: -Overall length: 5-1/4". Warranty: -1 yr warranty on material and workmanship.