This connector diode contains a blocking diode of the capacity of 20Amp button.The used to avoid the currents reflux, and consequently to preserve the expected life of our solar panel. This connector MC4 is classified as IP67. IP (Ingress Protection). This parameter is very important because it refers to both the level of resistance to dust and both the level of water resistance. The range of IP67 means that the device is fully protected against dust and can be submerged in water up to 1 meter for 30 minutes without any loss.