Exterior Box Cover Assembly 5-20R (Two-Circuit) â Exterior box cover assembly prewired with (2) 20A weather resistant duplex receptacles. Receptacles are wired on separate circuits with a shared neutral. NOTE: Installation requires double pole GFCI circuit breaker. When used in conjunction with the ground box body (XB814) the entire unit has a UL50E Type 6P & IP68 rating in outdoor locations. Black.