The Tektronix 067-0539-00 is a 24 pF input normalizer with BNC connectors.
Tek 067-0539-00 Top View
Tek 067-0539-00 Bottom View
Tek 067-0539-00 Inside View
Tek 067-0539-00 In Packaging
Tek 067-0537-00, 067-0538-00, 067-0539-00, and 067-0541-00