These extended length, low-profile Quick Change Chucks will fit right through an 11/16" dia. hole! Now you can easily bore deep holes using this Extended Shank Quick Change Chuck and a 3/4" or larger ball detent style drill bit. It also makes it easy to drive screws in previously unreachable places. Better yet, the ball detent hex shank allows you to "extend the extender," for a holder of almost unlimited length. Actual length of extenders is about 1/2" longer than stated usable length. Made in USA.