What This RP-SMA Plug Does on the Cable
It is a threaded, weatherproof connector rated to 12.4 GHz at 50 Ohm impedance. The kit ships with four pieces: the connector body, an end cap, a crimp ferrule, and a length of heat shrink tubing. That material stack — brass body, PTFE insulator, gold-over-beryllium copper centre pin — is the standard recipe for a connector that holds its impedance through temperature swings and repeated mate cycles.
Which Cable Does It Terminate?
This plug is listed for RG-174, RG-188, RG-188A, RG-316, LMR-100, and M17/119-RG174. Those are all 50 Ohm cables in the 0.100-inch to 0.110-inch jacket range — the same family a field tech would pull for a short jumper between a radio and an antenna. Match the crimp die to the ferrule OD for the cable you're using; the wrong die leaves the shield loose and the VSWR drifts.
The 12.4 GHz maximum frequency is the upper end of the specified bandwidth — the connector's geometry and dielectric maintain a 50 Ohm transmission line up to that point. The 500 mating cycles come from the gold-plated beryllium copper centre contact.