Nidus Cavity Sliding Door Lock Round Entrance Set Entrance Lock Kit is defined as a lock that can be unlocked by a key from the outside and inside. Suitable for external doors that need high-security locks, including front and back entrance doors, garage access, patios, and storerooms. Entrance Lock Kit Function - Outside key unlocks the outside knob, the inside knob is free at all times, push button locks the outside knob Features: Edge Pull included Concealed screw fittings Specifications: Backplate Diameter: 65mm Internal Diameter: 52mm Door Thickness: 31mm - 35mm Backset: 60mm Keying: 3 pin Available Finish: Matt Black Polished Chrome Satin Chrome