Material: Aluminum alloy and carbon steel Accepts accessory rotary bits with 0.012 inch(0.3mm) to 0.12 inch(3.2mm) shanks Easy and quick to change accessories replacement on multi tool without changing collets General usage: This keyless drill chuck is widely used along with various drill machines, milling machines, lathes, boring lathes and electric hand tools Excellent replacement or upgrade compatible with thousands of model Specification: Height :23mm Clamping Range: 0.3-3.2mm Size :7x7.5mm, 7mm refers to the grinding machine shaft outer diameter is 7mm, 0.75 is screw thread pitch is 0.75mm, your grinding machine shaft outer diameter measurements is 8mm, you can consider it. Package Includes: 1 Piece Drill Chuck