011-0066-00
The Tektronix 011-0066-00 is an Input RC Standardizer with BNC connectors for calibrating instruments with 1 MΩ // 20 pF inputs.
It must be attached directly to the instrument's input connector.
It was superseded by the 067-0538-00 Input RC Normalizer, which is identical except for the name and part number.
The 011-0022-00 (superseded by the 067-0533-00) is the equivalent with UHF connectors.