Locking system for shutters with sash seat adjustable from minimum of 85 to a maximum of 101 mm and available with various lengths of screws for fixing. The Super Top Grillo; the original shutter stop of the Esinplast, fully automatic during locking simply sending the shutter to the shutter stop; to unlock you must instead operate the special lever.Produced completely in thermoplastic material, to avoid the formation of rust, it has been tested to guarantee a high resistance to atmospheric agents and to the continuous opening and closing of the shutter. It can be applied on all the frames in aluminum, pvc, iron and wood. This system; available in 'with shock absorber' and/ or ' with increased dowel'; the first allows, in addition to dampen during closing the reception of the door, to eliminate the game and any noise between the latter and the fastener, the version with increased dowel allows instead to increase the height of that part of the fastener that determines the hold of the door during locking. The Super Top Grillo can; be easily mounted by creating a 10 mm hole for the insertion of the dowel needed to screw the fastener.