1. The sturdy and durable hinge is made of stainless steel, which is rust-proof, non-corrosive, and durable. Invisible design, simple and practical 2. The spring has high strength and durability, and the opening angle is 80°. For the upper lifting hardware support, it is suitable for folding beds, folding sofas, folding sofas, cabinet doors with lifting doors, etc. 3. Each package includes one left spring hinge and one right spring hinge. Does not include screws 4. 80 degree folding sofa bed cabinet hinge spring hinge,