This connector is specifically designed for connecting photovoltaic solar systems with high mechanical requirements and extreme weather conditions. For permanent installations.Renogy MC4 Cable Connectors are made with highest quality materials. They are both heavier and sturdier than many other brands, ensuring long term reliability and performance. These connectors are designed to complete a solar panel (PV) array, typically in parallel applications. These connectors are also waterproof and resist dust build up.