The TE Connectivity Greenpar 1-1478039-0 is a T-shaped BNC adapter — a BNC plug on one end splitting into two BNC jacks. It's a same-series (BNC to BNC) conversion adapter, meaning it joins two BNC cables or devices to a single source, or splits a signal line. The 75 Ohm impedance and 2 GHz frequency ceiling place it squarely in the video, broadcast, and CCTV domain — not the 50 Ohm world of RF test gear. The body is silver-plated brass, the centre contacts are silver-plated brass, and the dielectric is PTFE, giving it the temperature range and signal stability for rack-mounted or field video distribution.
The 75 Ohm impedance is the headline spec — this adapter is designed for 75 Ohm systems. Plugging it into a 50 Ohm line creates an impedance mismatch that reflects signal and degrades performance above a few MHz. The 2 GHz max frequency is typical for 75 Ohm BNC; at that frequency the PTFE dielectric and silver-plated contacts keep insertion loss manageable. 500 mating cycles is a moderate rating — fine for a semi-permanent install or occasional re-patching, but not for a daily-use test bench where you'd want a 1,000-cycle part.
The plug end (male pin) mates with any standard BNC jack (female socket). The two jack ends (female sockets) accept any standard BNC plug (male pin). It's a straight same-series adapter — no gender changers or series adapters needed. The bayonet lock is standard BNC; hand-tighten a quarter-turn and it's seated. The 500-cycle rating means the silver plating on the centre contacts will hold up through a reasonable number of mate-unmate cycles before the plating wears and contact resistance drifts.