From the technical point of view, the Primex system was identical with that of Märklin HO. A center-rail AC system with power take-off over point contacts in the middle of the track.

There were 10 VA and 30 VA transformers available. These were older versions of the Märklin transformers with a sheet metal housing, while the newer Märklin transformers got plastic housings.

When Primex started in the late 1960ies, the locos were simplified so much that the direction of travel could only be chaged by an manual lever! However, this way was left soon. The locos got a electromechanical reversing unit, like their Märklin counterparts. However this didn't mean the end of any technical simplification. So still less axles were driven or electric locos had no equipment for power-take off via catenary system.

The couplers were identical with those of Märklin HO as well. A loop and hook coupler compatible with those loop and hook couplers of other manufacturers, but equiped with an advance uncoupler tab.

When the name "Primex" was used for the first time in the catalogue of 1968, it was used as the name for the loop and hook coupler without the advance uncoupler tab. However this type of coupler was only used for a few models.