R1 WURKS R1-990371-1 DC1 Ball Cups Tight fit

These ball cups come in a set of 12.  Tight fit 

NOTE:

The fit of plastic ball cups can vary due to moisture content in the plastic and manufacturing differences between batches. As a result, you might find the fit to be slightly tight. If this happens, you can gently pinch the installed ball cup at several points around its circumference until the desired looseness is achieved. This process may need to be repeated periodically.