Mortice deadlock (Butters System of 1955) by Josiah Parkes and Sons Ltd of Willenhall
1978
Six-lever M6 mortise deadlock and key, 1973
Mortice escape deadlock (Butters System of 1955) by Josiah Perks and Sons Ltd of Willenham
1978
Chubb's five one-sided six leaver detector rim dead lock
1844
Tann's seven inch reliance-guarded seven lever one-sided detector dead lock with key
1843
Parson's balance lever double-sided rim dead lock
Eight inch five lever one-sided rim dead lock
Type M555 5 - lever mortice dead latch
Eight inch one-sided dead lock
1830
Mortice dead lock
Ten-lever 'Impregnable' rim automatic deadlock and keys
1973