What Is a Double Key Deadlock?

This deadbolt is used for additional security on external wooden doors. It is recommended that a deadbolt is always used in conjunction with a knobset

Double Cylinder Deadlock - Polished Brass

Lockwood 005 Deadbolt 24hr Melbourne Locksmith

Which is Best — Single or Double Cylinder Deadbolt Locks?

LOCK & KEY S205 DOUBLE CYLINDER DEADLOCK SATIN CHROME

Double vs Single Cylinder Deadbolt: What Are the Differences

How To Replace A Deadbolt Keylock

Double keyed Deadbolt Lock - Keyed on Both Sides, 2-Way Adjustable

Double Cylinder Deadbolt

Replacing double-keyed deadbolt with turn lever : r/Locksmith