The shank of the mandrel must match the size of the power tool collet or drill chuck, and the pilot diameter must be compatible with the size of the cartridge roll.
3M 45117, Cartridge Roll Mandrel, 3/16 in x 1 in x 1/4 in, 7000148243
$3.85
Factory Stock, 7-10 Day Leadtime
3M Cartridge Roll Mandrel is a tool attachment that holds an abrasive cartridge roll (sold separately). Together, the mandrel and cartridge roll enable the user to grind or finish hard-to-reach areas of a workpiece, such as angles and curves. The mandrel attaches to a rotary tool such as a die grinder or drill, and comes in different sizes to fit a variety of cartridge roll sizes.

Norton 61463622219 - 2" X 3" X 5/8"-11 Type 18, 24 Grit, GEMINI 57A24-R Aluminum Oxide Square Tip Abrasive Plug, 10 Each
3M 11419, Roloc Disc 361F, P240 XF-weight, TR, 2 in, Die R200P, 7000045105 
