This system combines the advantages of external roller shutters with those of top-mounted roller shutters. The main advantage of this system is that you can install it without enlarging window holes and install the box at the same time, which provides a visual effect that is similar to that obtained when using top-mounted roller shutters. In this type of roller shutter, the entire box is located outside the building and it can be accessed through an inspection cover located at the bottom of the box.  There are versions with and without an insect screen.