The IRWIN® 4935655 7/16-Inch Lock N' Load Quick Change Bit Holder 12-Inch Over All Length has a Carbon steel construction sleeve and body for durability and life. The Lock-n-Load system is designed for one-handed quick release to get the job done quicker. The Patented jaw design holds bits securely on 6-flatted shanks, as well as ball detent bits. The 7/16-Inch Lock N' Load works with 17-Inch Ship Augers (Sizes 9/16-Inch and larger), 7-1/2-Inch Short Ship Augers (Sizes 1-1/8-Inch, 1-1/4-Inch), Self-Feed Bits (All sizes), and UNIBIT (Sizes #5, #9, #13, #14, #20, #21)