Tired of the hassles of trailer plug ins? So was I!! So as with most products we find it is born out of a desire to find something better. These electrical connectors are used by the cities of Edmonton and Calgary on their fleets so figured they must know something. They are held together by rare earth magnets, have a double o-ring seal and don't have the tabs that get squished or bent over that hardly make a connection. Stop fighting with electrical plugs and try some EZ Connectors!