Size: Sly 80 (40 40) Description This door lock combines a carefully designed mechanism with durable materials to deliver reliable performance for a wide range of door types. All movable pins are made of nickelplated hardened steel to resist wear and maintain smooth operation over time. The entrance function with knob (open on one side) is easy to install or , making this lock suitable for installations and straightforward upgrades. Key benefits Durable internal components: All movable pins are made of nickelplated hardened steel for long service life and consistent operation. Reliable design: The lock is carefully designed to provide secure and dependable locking and unlocking. Wide compatibility: Fits wooden doors, metal doors, courtyard door locks, composite doors, aluminum doors, and French doors. Flexible use: Suitable for both lock installations and replacement of existing locks. Easy installation: Entrance function with knob (open on one side) simplifies installation and replacement work. Important attributes Size: Sly 80 (40 40) Material: Movable pins are nickelplated hardened steel Function: Entrance function with knob (open on one side) Compatibility: Designed for use on multiple door types including wooden, metal, courtyard, composite, aluminum, and French doors Performance: Engineered for wear resistance and steady mechanical performance Practical use scenarios Home front door upgrade: an old lock on a wooden or metal front door to improve mechanical reliability while keeping installation time low. Courtyard or garden gate: Install on a courtyard door or metal gate where durable internal pins help resist frequent use and environmental wear. Renovation of patio or French doors: Use during door renovations for composite or aluminum French doors where compatibility and straightforward replacement are required. Installation and replacement notes Designed for easy replacement of existing locks and straightforward installation for doors. Entrance function with knob provides onesided opening control, suitable where keyed access and a knob on the opposite side are required. This lock delivers a practical, durable solution for a broad range of door types, combining sturdy nickelplated hardened steel pins with a carefully designed mechanism for reliable everyday use.