The Enphase system is new way of inverter system which allows building up systems in almost any size by using only few different basic components.
In some installation scenarios (chimneys, dormer windows, etc.) it can be necessary to span a bigger distance than the clearance between two connectors of the Q-cable. In that cases, it can be a solution to order one Q-cable connector more and not to use this connector. This has then to be closed with the Q sealing connector.