Backup pad designed to support 3MÖ RolocÖ 3" diameter abrasive discs. This pad has a 1/4-20 INT thread which allows it to be mounted directly to tools with 1/4-20 INT thread which allows it to be mounted directly to tools with 1/4-20 EXT threaded shafts. Assembly also includes a RolocÖ shank and adaptor. Maximum operating speed: 20,000.