If your Sta-Rite 5P2R pump was fitted before 1998 then you can order the PS-100, unless the copper insert has already been removed. If your pump was fitted after 1998 there is a slight possibility that it was made before 1998. The physical difference is that pre 1998 models have a copper cone into which part of the seal fits and later models do not.
The easiest way to check is to separate the pump at the clamp and look to see if there is a cone.
If this is not possible, you can either order the PPS-200 and remove the cone if it is fitted or order the PPS-100/200 which has both ceramic ends in the pack.
In the situation where the cone is present but damaged , it should be removed and a PPS-200 seal , which costs the same as a PPS-100 seal, used to avoid the extra cost of replacing the cone.
This pack contains the ceramic ends of both a PPS-100 and PPS-200 seals. The 200 end is slightly wider and deeper than the 100 end and fits in the space created by the removal of the cone. The bellows end is common to both 100 and 200 seals.