These foam polishing bobs consist of two different styles of material. The green foam is a more aggressive, dense foam better suited for slightly dirtier wheels or the pesky corners of the forged wheels where brake dust collects. The black foam is softer, meant for a lighter cut, leaving no "buffer Trail" or holograms. You can use both materials for either application however these are the two I prefer when I am working on wheels. I recommend using only hand polish with these foam bits, no compound. 

To use these in an air tool with a 1/4 chuck, purchase this 1/4-1/8 adapter - Please check to make sure one of these will fit your specific machine. Singl
4 Pack 1/4" To 1/8" Die Grinder Collet Adapter Die Grinders Accessories Attachments 1.06 X 0.53 Inch 3mm, 6mm (Silver) - Amazon.com

Content: 5 green, 5 black

MAX RPM: 15000
SHANK SIZE: 1/8