Electrical 55 Amp Electric Upgrade 7355Ru Parallax Power Supply, Llc 7300RU Replacement Upgrade Converter and Charger 55 ampere is an easy upgrade to clean,quiet and clear D.C. power. 7300RU Series converter and charger sections make it easy to upgrade 6300 series linear converters. By simply sliding into the bottom of existing 6300 series models, 7300 RU converter sections provide whisper-quiet operation. Clean power free from spikes and surges. FCC-certified to minimize interference with TVs, radios, and emergency channels. Its easy to slide into the next century. All Parallax products carry a standard two-year warranty.