Oreck grip pad or drive pad holder. 
 
This black plastic pad block fits on the bottom of Oreck Orbiter Floor Care Machines. Designed to securely hold a variety of scrubbing pads in place with its plastic teeth.
 
Orbiter 12" pad driver
Item Package Dimension: 10.699999989086" L x 7.799999992044" W x 1.599999998368" H
Item Package Weight: 0.59965735264 lb
Model Number: 53178-510327
 
Will fit ALL Oreck Orbiter models including but not limited to: ORB550, ORB600 and ORB700