Lockable window cranks are mechanical locks that are placed on windows to help secure a building. They are made of metal or plastic and have the shape of a small crank or hook that is placed on the inside of the window. The crank or hook is locked into a hole in the window frame, making it impossible to open the window from the outside. Lockable window cranks can be used to prevent burglars from forcing the window open or to prevent the window from accidentally opening, such as with children or pets. They are easy to install and are an effective way to increase the security of a building.