Mounts are not glass, they are card frames.
They are a total size of A4 and leave an aperture of 9"x6", which means the map design is smaller than an A4 unframed.
They are not removable so be sure you want them (unless you ask for them unstuck)
They are best for quick gifts you do not wish to frame. They are not the best if you plan to find your own A4 glass frame.