The Flex XC3401 VRG 111mm (approx. 4 3/8") Backing Plate. The plate is designed specifically for this polisher, and creates the forced rotation that sets the FLEX apart from other dual action buffers.
Recommended to work with 5", 5.5" polishing pads.
The special fixing allows use of this pad only with the XC 3401 VRG.