The Guardian Privacy door knob set is designed to replace Weiser door knobs. Weiser door knobs were commonly used in the 1970's and 80's. Weiser use a very specific latch system which requires a large portion of the door to be removed. This can mean it is very difficult to find replacement knobs without reconstructing and filling your doors. Privacy set has turn button on the inside and emergency release slot on the outside and is perfect for bathroom/toilet doors as it locks safely.