30A Anderson Powerpole Connector Red & Black Pair
 
Anderson Powerpole connectors are very handy for small scale off grid solar power. 
They are reversible which means there is no seperate plug and socket, instead just flip one upside down to plug it into the other. 
 
Wire Size: AWG16 - AWG12
Voltage Rating:  600V DC or AC
Current Rating: 30A