Stainless Steel. The Eff Eff 351M.80 electronic swing door strike is equipped with an innovative quiet electric motor drive and is designed for the locking of swing, double swing, and carousel doors. It is suitable for horizontal or vertical installation in the door frame, comes supplied with face and counter plate and is fail unlocked.. 12V DC to 24V DC multi-voltage - controlled DC voltage. Holding force of 5000 N. Very quiet locking and unlocking, silent during permanent release. Compatible with Model 351U