A generic R100-series receptacle for the 100 mil (2.54 mm) grid with a wire-wrap termination. It is pressed into the fixture's probe plate once and the spring probe seats in it, so a worn probe can be pulled and replaced without unsoldering or rewiring the fixture.
100 mil is the workhorse grid for in-circuit test, and the R100 pattern is what most generic probes of that size are built to, matching the standard 1.7 mm drill used by branded 100 mil bodies. The wrap post suits fixtures wired on a wrap gun; within the R100 range the numeral marks the body length variant, so check the overall length against your plate stack before substituting one R100 for another.
Generic R100 series, for 100 mil (2.54 mm) test-point pitch
