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. It will attenuate a 1 ns rise-time pulse in a 50 Ω system with negligible distortion.