Parallax | 50 Amp Transfer Switch | ATS503Take the hassle and risk out of switching between shore power and generator power with the Parallax ATS503 50 Amp Automatic Transfer Switch. Designed specifically for 50 amp, 120V electrical systems, this transfer switch automatically routes power between your two sources, so you never have to handle plugs, swap cords, or fumble with breakers when switching power on the road. Reliable, Automatic Power Transfer The ATS503 is the most trusted way to