One PowerPort controls one 20 amp circuit - an unlimited number of additional 20 amp circuits may be controlled by adding more PowerPorts. * Turn-on or turn-off sequence is initiated by a simple switch closure - switches may be momentary or latching. * Can use multiple remote on-off switches for multi-location control. * PRO-Series level spike and surge clamping and EMIRFI filtering provides the most comprehensive power protection available anywhere. * High reliability 25 amp relays.