N1411A is a connection cable with a 4-pin socket to a 6-pin round plug and is required for the two devices B2985A and B2987A in order to be able to connect the 100 GΩ evaluation box N1422A. This cable is included in the evaluation kit N1299A-301.
If an external voltage source is used in conjunction with the 100 GΩ resistor, the current values for the two devices B2981A and B2983A can also be verified with the corresponding evaluation kit.