This is a Corbin Russwin 1000 series mortise cylinder. It threads into a mortise lock or other mortise-style hardware and turns a cam to operate the lock. It is a conventional keyed cylinder for replacing a worn or re-keyed cylinder at an existing opening. Part 1000-234-A04-6-77 722 is the 77 Keyway A04 DL4000 Deadlock, Sargent Cam version in Black Oxidized Bronze.

• 77 Keyway A04 DL4000 Deadlock
• Sargent Cam
• Finish Black Oxidized Bronze
• Part number 1000-234-A04-6-77 722