This Jacobs Hand-Tite drill chuck is a great addition to your toolkit. It has a 1/2 inch threaded mount size and is made in the USA. The keyless chuck type makes it easy to use and the drill chuck type is perfect for any drilling job. The California Prop 65 Warning is included and can be found on www.P65Warnings.ca.gov. This drill chuck is suitable for use in various industries such as CNC, metalworking and manufacturing.(q)