The stabilizer/elevator combination represents the main vertical control surface of the aircraft.   The elevator portion is connected to the control handle via the lines, bellcrank, pushrod, and control horn and responds to the pilot's hand movements.  Raising the hand pulls the up line which causes the aircraft to gain altitude.  Lowering the hand pulls the down line and causes the aircraft to lose altitude.   All aerobatic manuvers are based on these two movements.   The elevator is hinged to the stabilizer to allow this movement.   Traditional over and under cloth hinges are supplied in the kit.   More advanced builders can substitue a variety of after market hinges.   Regardless of the hinges used, be certain that the elevator moves freely and that the stabilizer/elevator assembly is installed square to the fuselage and level.