Digitrax PS2012 20 Amp Power Supply 12 to 23 VDCThis big regulated power supply delivers more power with less heat for more efficient booster operation. 20 Amp PS2012 regulated powersuply is usable with all scales to operate up to 4 Five amp boosters. PS2012 Features: Operate one or more boosters Scale selectable switch for use with N,HO or large scale Design Coordinated for use with Digitrax products Built-In unit over-curren and over-temp protection DC Output Current Ammeter On/Off switch Integral Cooling fan One "Y" cable (p/n YC52) Included for convenience with dual 5 amp protected outputs