The 31-9 is a BNC Jack to BNC Plug UG-306/U right-angle RF adapter featuring silver-plated beryllium copper contacts. Its body is made of brass with a nickel-plated finish, and it includes a PTFE insulator. Designed for connecting two dissimilar RF interfaces, this adapter is suitable for RF communication applications. It has an impedance of 50 ohms and operates within a temperature range of -65°C to 165°C.