It's always a good idea to have spare parts on hand in case of breakage, that is the potential represented by the 5251827 R10/20 Packing Kit. This kit includes two packing cups, four cylinder gaskets, two cap screws and 2 O-rings. This is enough to handle most pumps you may use, though if you need supplies for the R20/20 pump, then you should order two of these kits.