Cremone bolts are typically used on exterior french doors or windows. Wilmette Hardware has several extremely well crafted cremone bolts for your project.
They can be mounted either on the stile of the door or on the astragal. Often rabbeted doors are used for a traditional detail.
The geared action in the ‘cremone box’ was developed in France to allow two surface bolts to articulate locking or unlocking the door by using one lever or oval knob.