I have 1 also, since it already has a 600 ohm transformer and decoupling caps built in I added 2 BNC connectors to the top. One connected to the transformer the other using the caps as the input.

I have used this thing to monitor just about every type of circuit I have ever ran into.

Why BNC connectors you ask, I do mostly radio work and almost all of our test leads have BNC connectors on them so the chassis mount BNC was ideal for me.