Configuration of the 'stack' or 'sash' that remains when the retractable security grille is open
Single Sash Left: One retractable security grille locking to the left (viewed from the inside) is used to secure the window or door.
Single Sash Right: One retractable security grille locking to the right (viewed from the inside) is used to secure the window or door.
Double Sash: 2 retractable grilles are used to secure the window or door. The grilles lock in the centre.
Fixed Grille: Non retractable security grille, can be used if no access is required.
