It is a maintenance test set for the F/TF-102 series. used to control the launcher rails, their cycling up/down, while the aircraft is on the ground. Usually the MG-3/10 Fire Control System cycled the doors and weapons. However, safety switches in the right main gear blocked this action. This test set allowed the bypass of the lockout, and the doors and rails could be cycled. A routine process used when loading / unloading weapons and some maintenance actions.