6" Coring Bit Extension 5/8" Thread For Concrete Core Drill #12 - DRILL DEEPER! 5/8" 11unc Female end fits compatible drills (Not for Bluerock Z-1 Drills) 5/8" 11unc Male Threaded end fits BLUEROCK Dry type core bits as well as other compatible threaded coring bits Solid all metal construction Total Length: 6 3/4” From spindle shoulder to female thread end: 6” The Core Bit is shown for scale and not included with this adapter. Please see our separate listing for core bits and core bit packages.