15-foot PV wire extension with older generation MC3 connectors by Colorado Solar. Your best bet is to use MC4 connectors, but if you need to connect to MC3 connection, this extension is for you. This may be used to extend one wire 15 feet to another MC3 connection, or cut in half to extend both positive and negative wires 7.5 feet to normal wire connections (circuit breaker or bus bar in combiner box for example).