Euro Profile BS Double Cylinder Deadlock - Complete Set with Double Cylinder and Security Escutcheon. BS Deadlock 64mm and 76mm options. British Standard BS3621 Rated Dead Lock used as a matter of course by the national house builders. This lock provides a high degree of security and carries a 25 year mechanical guarantee. It has been CE and Certifire tested. Suitable for use in all domestic, industrial and commercial environments.