Often simply referred to as a "GenRad connector", the GR-874 system of coaxial connectors is a sort of RF tinker-toy set that you could use to glue various oscillators and whatnot together in test setups, often in combination with some custom electronics. An interesting feature of the 874 connector is that it is Hermaphroditic (there is no male and female), so gender-changers are not needed. At the time it was designed, it also had superior high frequency microwave performance.
If you posses legacy GenRad equipment that requires servicing or repair, we can replace the GenRad-874 connectors with BNC, binding post or other terminals.