Function: The front door knobs have a small twist knob on one side to lock the door and a lock and key mechanism on the other side of the door. Durable: The heavy-duty construction of these door handles allows them to be strong, sturdy and long-lasting. Sturdy knob design prevents breakage and breakage that can occur with inferior mortise door handles. The chrome finish adds a stylish touch to your home or office. Security: These chrome door knobs provide extra security with the lock and key mechanism. They are ideal for offices, bedrooms and interior porch doors as they provide optimum security. Application: These door latches can be used on interior or exterior doors that are 35 thick. at 45mm. The tubular latch is adjustable to 60mm (the distance between the center of the hole and the edge of the door). They are suitable for commercial and domestic use. Contents: 1 door lock and 3 keys