Probrico crystal door knobs are made from zinc and clear crystal glass, and the rosette and crystal knob are clear reflective and fit a variety of decoration styles. It is a single knob which fixed on the door, you don't need to turn the knob or operate a latch, it is usually used for bi-fold doors, french doors, and closet doors. If you need other functions in this style, we also have privacy and passage crystal door knobs, you can use the same style of knobs to decorate your room. Please don't worry if you have any problems after receiving the knob, please feel free to contact us, we will try our best to solve the problem.