The Protege Half DIN Rail 2 Door Reader Expander delivers up to 4 reader inputs and 2 locking device outputs, in a compact two-tier half DIN rail design. With 8 inputs that can be used for extended monitoring functionality, and 6 open collector outputs available for management of controllable devices, the Reader Expander features extensive hardware advancements that support flexible security and access control, alarm monitoring and building automation. 2 doors (4 readers) 8 multi purpose inputs 2 Form C relay outputs 6 low current outputs