067-0511-00
The Tektronix 067-0511-00 is a variable attenuator which has the end terminals of a 100 Ω potentiometer connected from input to ground and the potentiometer divider arm connected to the attenuator output.
The attenuator is not matched to any particular impedance system, although input and output are 50 Ω GR-874 connectors. It will attenuate a 1 ns rise-time pulse in a 50 Ω system with negligible distortion.