The Schneider Electric (Erie) AH23B020 is a 120V normally open (N/O) spring return (S/R) actuator. The "Hco" likely denotes a specific configuration or application within Erie's product range. This actuator is designed to control valves or dampers in HVAC or industrial systems. Being normally open means it's open when de-energized and closes upon receiving power. The spring return fea... https://www.partshnc.com/ah23b020-schneider-electric-erie-120v-no-hco-sr-actuator