The LCN 4640 Auto Equalizer is a smart and reliable electrically powered low-energy power operator. It provides easy access for people with disabilities or the elderly. The 4640 is designed primarily for manual opening applications that occasionally require automatic opening.Adjustable spring size 2-5Strikes a seamless functional balance of controlled access combined with free egressCast iron cylinder with all-weather fluid for consistency and reliabilityHighly efficient motor combined with a custom designed gear system provides exceptionally quiet and smooth operationFunctions as a full featured door closer when not actuatedBuilt-in delay allows the strike to release before the door begins to openDesigned for both the power and coordination for card reader and electric strike applicationsProvides both accessibility and security for building occupants