Handa HD PV Panel Mount On-Board Connector is the 3rd upgrade version of Handa HD HDC4 panel mount PV Solar connectors,updated the size from M12 to M20, nut rear locking to easier front locking and making the copper pins' crimping type to advanced pins panel soldering on-board.the pins is all-in-one style without any breakpoint(Reduce the risk of burning caused by poor contact).