Features and Benefits:?9 inch x 1/4 inch x 5/8-11 inch?A24R Type 27?Comprehensive offering for general purpose to specialized high performance applications?Consistent performance from wheel to wheel through superior manufacturing processes?Tested for balance, resulting in smooth, vibration free grinding and cuttingDepressed center - cut-off/raised hub wheels type: 27 diameter: 9 width: 1/4 hole size: 5/8 - 11 material: aluminum oxide maximum RPM: 6600 grit: 24 trade name: Milwaukee.