... -breaking, deburing, 3.porting and polishing. 1/4"air die grinder Free speed:22,000RPM air consumption:5CFM Hose size:3 ... MT-2029k 16PCS 1/4" AIR DIE GRINDER 1pcs-1/4" air die grinder 10Pcs-Mounted Stone 1pc-nipple 1pc-mounted Stone ... Holder 2pc-Allen wrench 1pc-blow mold case 1/4" Air Die Grinder ...