The raintight NEMA 3R power inlet box is designed for the use with the Pro/Tran transfer switches and Reliance Panel/Link manual transfer panels and generator-ready load centers. The power inlet box may be installed indoors, or outdoors in an open area where the generator is being used. Using one of the four combination 1/2-inch and 3/4-inch knockouts (one on each side, bottom and back) the power inlet box can be wired directly to the transfer switch or panel. The exclusive patented design provides generous wiring space and facilitates rough-in. The PR Series includes circuit breakers that match the amperage of the power inlet. UL listed.