Reliance Controls Corporation PB20 20-Amp NEMA 3R Power Inlet Box for Generators Up to 5,000 Running Watts For indoor or outdoor use with specific transfer switches, manual transfer panels and generator-ready load centers Outdoor, raintight NEMA 3R non-metallic power inlet box provides generous wiring space Maximum generator running watts: 5,000 Maximum generator input: 20A @ 125/250 VAC UL listed, exclusive patented design facilitates easy rough-in