Logas 5-19mm 1/4 to 3/4" Stud Extractor Broken Screw Bolt Puller Removal Tool 1/3" Dr. Grips studs up to 3/4" diameter Removes studs, rounded nuts or bolts Cam lock system grips securely, won't bind Hardened teeth with black oxide finish Hole diameter: Big appr 19.6mm, small appr 14mm