The RIDGID 4-1/2 in. x 1/16 in. x 7/8 in. (115 mm x 1,59 mm x 22 mm) metal cut-off wheels come in a 10-pack and are designed to be used on right angle grinders. They are designed for type 1 wheels. The discs have a max RPM of 13,580. They are great for metal fabrication, cutting, and body work.