Before the photovoltaic energy connectors are present, the connection of photovoltaic power plants is mainly completed by the "splice" (screw terminal or joint connector) method. With the development of the industry, the industry's demand for fast, safe and easy-to-operate connection plans is becoming more and more intense.

In 1996, a new type of plug-in connector came into being, which is the Stäubli MC3 photovoltaic energy connector. Junction box supplier MC3 is a photovoltaic energy connection product in the real sense. It is two completely different connection methods from "splice". Its meaning is to re-define the connection of photovoltaic modules. In 2002, the Stäubli MC4 was launched, again re-defining the photovoltaic energy connector, it truly achieved "plug and play" (plug and play). As the requirements of the photovoltaic power station system are getting higher and higher, it is inevitable that MC4 will appear and replace MC3, whether it is from the standard level or the safety level. Since MC4 was developed and introduced to the market in 2002, it has been successfully applied for nearly 17 years and has gradually become a norm in the profession. At present, there are a wide variety of connector products on the market, but most of them use the MC4 style in terms of structure and appearance, so we can call it "MC4-like".