Straight-Line 6In Ext. Die Grinder 1 Hp, Horsepower 1 hp, Collet Size 1/4 in; 6mm, Grinder Orientation Straight, Max. Speed 12,000 RPM, Air Inlet 3/8 in NPT, Includes 1/4 In. Collet Insert Mfr. No. 50013 and 6mm Mfr. No. 50016, Fits Optional 1/8 In. Mfr. No. 50065, 3/8 In. Mfr. No. 50014, 8mm Mfr. No. 50039, Safety Features Safety Lock Lever, Power Source Air Powered