This board is intended to periodically verify proper resistance measurements of the CableEye tester or after performing a calibration.
A set of resistances and a couple of diodes cover all 64 test points to ensure that none of them is off-measuring. This board is sold as a single board, not a set of 2. You should manually plug the board to the second bank to cover all test points.
If you have expansion modules, plan ordering a CB Board Extension Cable, item 856 to be able to move the board down the expansions.