Gates Carbon Belt Drive QR Snubber 
The snubber prevents skipping of the belt on the rear sprockets
Suitable for hubs with quick release axle and dropouts without hangers
Made for applications up to 142mm (anything larger requires a spacer kit)
Rolhoff requires these for use with their hubs when using belt drive. Suitible for  Rohloff Speedhub 500/14, XL 500/14, XXL 500/14, and others
NEW IN PACKAGING
 
MPN: CDECDQ