Innovative shutter stop for shutters and shutters in aluminum provided with a frame that allows the locking of the door after a rotation of 180°. Completely retractable because, when the sash is closed, it is not visible, easily usable by the user who must not lean out during locking and unlocking. Available in the right and left versions (the back is determined by the opening of the sash remaining inside the building) for camera profiles C.E. decentralized. This system can be applied, through simple processes, both on installed and non installed fixtures. The sash on which it is to be applied must have a width greater than 430 mm, a fundamental requirement for operation. The wall does not need to be drilled for installation. Therefore, it is ideal for application in buildings treated with thermal wall.