Pad Driver to fit 21" Model Floor Machine Buffer/Polisher/Scrubber. Comes with Riser and NP-9200 clutchplate Installed.20" Pad Driver Commercial Contractor Quality Floor Pad Driver, complete with riser and mounted clutchplate. Super strong, and rebuildable if the need arises. Comes with NP 9200 clutchplate to fit most modern floor buffers. Measure the outside skirt of your buffer, and select a paddriver to match that measurement. Designed to hold floor pads securely in place when polishing, scrubbing and stripping floors