DEWALT IMPACT READY Locking Bit Holders provide users exactly what they need when fastening or drilling with 1/4; hex-shank accessories. The locking mechanism securely keeps the accessory in place during use and the quick-change features makes it easy to change accessories on the job. Robust magnetism provides optimal DEWALT DWA12HLDFT-Drill Bit Holder Extension, Impact Ready, 12-Inch