Taylor 1/8" Drill Chuck. Comes with key & adapter. The adapter is tapered on one end to fit the chuck and has 1/4-28 threads on the other end to fit the tool. This chuck fits the T-9750, T-9750EX, T-9751, T-9753, and T-9754. Key is model T-9750-B. Chuck only is T-9750-A. Adapter is T-9750-D.