Non-Metallic Power Inlet Box, 50 Amps, Reliance Controls Pbn50. The Reliance Controls PBN50 50-Amp NEMA 3R CS6375 Power Inlet Box is a watertight electrical inlet box designed to be located outdoors where the generator is running in order to prevent dangerous carbon monoxide fumes from entering your house or other cherished space. This inlet box should be safely hardwired through an outside wall directly to the transfer switch or panel, eliminating the need for cords running through windows or doors. It was also designed to be wired directly to the transfer switch or panel by using one of the four included combination 1/2-inch and 3/4-inch knockouts (one on each side, bottom and back). The exclusive, patented make provides generous wiring space and facilitates rough-in. The face of the box is removable for easy placement and wiring and, finally, it was constructed of steel with rugged, anti-corrosive, powder-coated paint and has a spring-loaded inlet cap to prevent moisture front entering the front-mounted connector inlet when not in use. Since 1909, Reliance Controls Corporation has contributed more innovations that any other single manufacturer and has been awarded over 85 patents on manual transfer switches, time switches and accessories. Reliance Controls Corporation specializes in the manufacturing of a wide variety of electrical products. The primary product line consists of heavy duty time clocks and controls, generator accessories, transfer switches and transfer panels for portable generators. And after over a century of innovation, Reliance Controls Corporation has built an enviable reputation for high quality, superior engineering and exceptional customer service. Cabinet type: NEMA 3R Must be installed outdoors near an in-use generator Durable, raintight, and non-metallic power inlet box Designed specifically for generators up to 12,500 maximum running watts