Self -locked function to secure the safety.
Optional for power springs to open the mechanism.
Anti-drop metal slides for easy to close and open.
Optional for comfortable seat box.
SEC00# doesn't has power springs and seat spring frame to save your cost.
Optional for metal seat box for better feeling seat.
Storage hinge is for sectional seat, there are 2 or 4 power springs optional.
Attention: You're suggested to add over-hangings both sides to hide the mechanism .