Quick-Change Chuck Extension, 2 x 1/4-In.

1/4" quick change 2" extenstion, patented jaw design holds bits securely on 6 flats as well as ball detent bits, lock-n-load system for one handed quick release, 1/4" range holds insert bits, carbon steel construction sleeve & body for durability & life, fits all irwin speedbor blue grooves, speedbor max sizes: 7/16" to 1-1/4", all fastener drives, unibit sizes: #1, #2, #10 & #12, 1/4" hole saw arbor sizes 9/16" to 1-3/16", countersinks size #4 to #12.