FUNCTION: The door handles feature a rotary knob on one side for internal door locking and a safety release mechanism on the other side. The door can be locked and unlocked from the inside with a simple turn of the knob. These handles are designed for interior doors, providing security and privacy. DURABLE DESIGN: Constructed for strength and durability, these door handles offer a solid build that resists rattling and breakage commonly found in lower-quality mortise door handles. The polished brass finish provides a sleek, elegant appearance suitable for homes or offices. SAFETY: The exterior side of the door knob includes a safety feature. Using the included override key, the door can be opened quickly and safely from the outside in emergency situations. This locking mechanism is not intended for regular lock and unlock operations with standard keys. APPLICATION: Suitable for interior doors with a thickness ranging from 35mm to 45mm. The tubular latch is adjustable to fit 60mm or 70mm backset (distance from the center of the bore hole to the door edge). Ideal for both residential and commercial use. INSTALLATION: These door handles come with installation instructions and templates for easy setup. All necessary hardware is included, such as color-matched screws, tubular latch, and override key. The set is reversible and can be installed on both left-handed and right-handed doors.