Suitable for use with chucks/collets on all portable power and air tools. For use with spiral bound abrasive sanding bands. Self expanding when in use for a secure grip on the band. All shanks are 6mm - except where marked * which has an 8mm shank. Features and Benefits: Self expanding when in use for a secure grip on the band. For use with spiral bound abrasive sanding bands. Suitable for use with chucks/collets on all portable power and air tools.