A generic R75-series receptacle for the 75 mil (1.91 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.
The R-series is the industry-standard pattern most generic 75 mil probes are built to, so a plate drilled for a branded 75 mil body takes it as well. Within the R75 range the trailing letter sets the termination — W for a wire-wrap post, S for a solder cup — and the numeral marks the body length variant, so check the overall length against your plate stack before substituting one R75 for another.
Generic R75 series, for 75 mil (1.91 mm) test-point pitch
