It was very easy to find the parts I needed at reasonable prices. I will use this website again for grill parts.
Media retainers for: cp18,cp20,cp25,cp35
Media retainers for: cp18,cp20,cp25,cp35,cp65 & cp70 (set of four - includes disk & stem)
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.