... efficiency; Suitable for any access control system (reader, exit button, intercom); 180FA installation way is flushing concealed way,pls ... for Shell: Anodized aluminum & surface texture processing;Finishes for Magnetic: Zinc;Finishes for Armature: Zinc;Signal output: Dry contact, ... efficiency;Suitable for any access control system (reader, exit button, intercom);Easy to install, no frame door can choose ...