Core Bit Extension 24" Length - Extension for Core Drill Motors 1-1/4-7 Thread - Concrete Core Drilling Extension 24"TE724 Core Drill Extension Model Used for concrete core drill bits with 1 4 7 thread to be extended 24 in. 2 Ft. 1 4" 7 Thread x 24" Length Wet Drilling Core Bits Dry Core Bits Adapter 12" Ft. Core bit extension Compatible with Standard Core Drill Motor Shafts Compatible with Standard Wet Core Drill Bits Quality Heat Treated Steel Long Thread Durability