NO Mode DC 12V, ZOTER Deadbolt Strike Electric Drop Bolt Timer Door Lock Fail-Secure Superior low temperature design, long serving time It is made from durable and high aluminum lock body and stainless steel bolt.durable for use With door close time delay function, will lock until the door completely stop moving, rather than lock instantly, effectively protect the door and lock from damage Fail Secure mode, the door will unlock while supplied with power, and lock without power Suitable for : wooden door, glass door, metal door, fireproof door, etc