Window fasteners are suitable for use on more traditional windows that don’t have an internal locking mechanism. Most fasteners are kept in place with a mortice plate that is recessed into the window frame and are partnered with matching window stays. Windows with a central mullion use a fastener and hook plate and fasteners that have a night venting facility use a wedge plate to allow the window to be held open. Some window fasteners are lockable by tightening the grub screw which holds the fastener in a closed position. Security can be added to windows without a locking fastener by using window bolts or locking stay pins.
