What's in the Kit — and What Cable It Fits
That's everything you need to terminate one cable end — no separate parts to order. The cable group is specific: RG-179, 179A, 179B, 187, 187A, Belden 9221, or M17/94-RG179. If you're working with RG59 or RG6, this is the wrong plug — the ferrule and centre pin diameters won't match. The shield is crimped; the centre contact is soldered.
Both are 1-port, male pin, bayonet lock, 500 mating cycles, nickel-plated brass body, and active. The critical difference is impedance: 75 Ohm (31-70261) vs 50 Ohm (31-315-RFX). A 75 Ohm plug on a 50 Ohm cable creates a mismatch that kills return loss above a few hundred MHz. The 31-70261 also runs to 4 GHz with 0.1 dB insertion loss; the 31-315-RFX is spec'd to 4 GHz with 0.2 dB loss, but that's at 50 Ohm. The 31-320-RFX is another 50 Ohm sibling for RG-58 cable, with a crimp or solder centre contact option. If your BOM calls for 75 Ohm, the 31-70261 is the correct pick — don't substitute a 50 Ohm variant.