FUNCTION: The front door handles have a small turning knob on one side to lock the door and a lock and key mechanism on the other side of the door. Entry door knobs are used for interior or exterior doors requiring additional security. The door can be locked and unlocked from the outside using the key or from the inside using the snib function. DURABLE DESIGN: The sturdy construction of these door handles allows them to be strong, strong and durable. Heavy duty knob design prevents slamming and breaking that can occur with inferior mortise door knobs. 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 home offices, bedrooms and interior porch doors as they provide optimum security. APPLICATION: These door locks can be used on interior or exterior doors with a thickness of 35mm to 45mm. The tubular latch is adjustable to 60mm or 70mm (the distance between the center of the hole and the edge of the door). They are suitable for both commercial and domestic applications. INSTALLATION: This set comes with fitting instructions and templates for easy installation. All fixtures and fittings supplied including color matched screws, tube latch and 2 keys. This set of knobs can be used for doors on the left or on the right. Quantity supplied: 1 piece