The 131-3701-406 is an ear-mount bulkhead RF connector pack assembly manufactured by Johnson/Cinch Connectivity Solutions. It features a brass body with nickel plating (0.0001 MN over) and copper plating (0.00005 MIN), brass contacts with cold plating (0.00003 MN over), nickel plating (0.00005 MN over), and copper plating (0.00005 MIN), and a Teflon insulator with phosphor bronze washer components. The connector is rated for 50-ohm impedance across a frequency range of 0–4 GHz, with a maximum working voltage of 335 VRMS at sea level and dielectric withstanding voltage of 1000 VRMS minimum. It operates reliably over a temperature range of -65°C to +165°C and meets MIL-STD-202 environmental standards for thermal shock, corrosion, shock, and vibration. The connector features an initial engage/disengage force of 14 LBS maximum with 2 LBS minimum disengagement, a contact retention of 4 LBS minimum axial force, and a durability rating of 500 cycles minimum, making it suitable for demanding RF applications in military and aerospace environments.