The DY22 is a fail secure solenoid bolt lock with follower and provision for a EURO-cylinder override. Designed for simple installation and operation, this lock is specially accredited by the Rabbinical Court of Paris for use by Jewish people during Sabbath. Unusually, for a lock of this type, power is not required on the door leaf. The innovative design means the keeper houses the electronics, so there is no need for door loops. The DY22 is suitable for both single and double action doors.