The RYOBI 1/2" inch Single Sleeve Keyless Chuck A10KLC1 is a high-quality drill chuck designed to fit most 1/2" 20 mount drills. This unit features a threaded mount and a keyless chuck type, making it easy to install and use. With the trusted RYOBI brand and a unit quantity of one, this drill chuck is a reliable toolholding solution for CNC, metalworking, and manufacturing applications.