The Molex 0731485003 is a BNC T-shaped adapter from the 73148 series, configured as a single BNC plug (male pin) splitting into two BNC jacks (female sockets). The 50 Ohm impedance matches standard RG-58, RG-174, and LMR-200 coax cable systems — the impedance is the first thing to check before wiring it into a signal chain, because a 75 Ohm adapter on a 50 Ohm line will reflect signal power at the junction.
The body is zinc alloy with a nickel finish — nickel stands up to repeated bayonet coupling without galling the threads, and the zinc casting keeps the weight down for a free-hanging inline adapter. Center contacts are brass and phosphor bronze, both gold-plated. Gold on the mating surfaces keeps contact resistance stable across hundreds of mate-unmate cycles; the phosphor bronze spring fingers in the jacks maintain grip as the connector ages. The dielectric spacer between center and outer conductor is polypropylene (PP), a low-loss RF material that holds the 50 Ohm characteristic impedance across the junction.
Free-hanging (in-line) mounting — there are no panel flanges or threaded holes. The adapter hangs on the cable assembly, supported by the bayonet locks on both ends. Each end uses a standard BNC bayonet lock: a quarter-turn couples the plug to a jack, and the two jacks accept standard BNC plugs. The center gender is female to male — the plug end has a male pin, each jack end has a female socket. That means it mates directly with a standard BNC jack on one side and two standard BNC plugs on the other, no gender-changing adapters needed.