Quality Materials: The sofa functional hinge is made of high-quality metal iron, which is rust-proof, wear-resistant, corrosion-resistant and durable. Unique Design: The sofa functional hinge has a porous design and can be installed with multiple screws, which is safe and reliable. With elastic spring, the fine tooth pattern design is more flexible. Classic Style: The sofa functional hinge has a classic modern style, simple and natural, and complements the retro, industrial, country style and modern Nordic minimalist decoration. Product Usage: Unique sofa functional hinge, used for the connection of the backrest and tilt of the sofa, the height of the sofa backrest is adjustable, used to connect the armrest and seat, the backrest and seat, the cushion and backrest, the armrest and backrest, the frame and the bed.