FRONT SEAT HINGE MADE OF 3 STEEL SLOTTED PLATES, THE MIDDLE PLATE SLIDES W/MOVEMENT OF SEAT. WITH SEATBACK IN AN UPRIGHT POSITION ALL THREE SLOTS LINE UP, ALLOWING CHILD TO EASILY INSERT FINGER THROUGH HOLE. UPON MOVING SEATBACK FORWARD, MIDDLE PLATE SLID, AMPUTATING CHILDS INDEX FINGER.