BJ21

TROMPETER  BJ21..  射频/同轴连接器, BNC同轴, 直型隔板安装插座, 焊接, 50 ohm

The is a 50R insulated straight rear-mount BNC Bulkhead Cable Jack with solder pot and gold-plated beryllium copper contacts.

Newark:
# TROMPETER  BJ21  RF / Coaxial Connector, Insulated, Rear Mount, BNC Coaxial, Straight Bulkhead Jack, Solder, 50 ohm