Features: High quality adjustable hinge with 3 to 5 gears and a maximum angle of 180 degrees. Offers 7 available combinations. Suitable for sofas, beach chairs, fishing chairs, folding beds, and other folding furniture. Spring-driven mechanism allows smooth adjustment of armrests, backrests, pillows, and seats. Constructed from high-quality iron for durability. Smooth edge design with no sharp edges or corners, providing enhanced safety and appearance. Specifications: Material: Iron Surface Treatment: Zinc-White Plating Color: Silver (as shown in picture) Hole Size: 6.5mm / 0.26inch Length: 15cm / 5.90inch Pipe Diameter: 16mm / 0.63inch Thickness: 2mm / 0.08inch Gear Part Thickness: 2.3mm / 0.09inch Number of Gears: Positive 3 Gears, 45 Degrees / Third Gears 180 Degrees / Diagonal Third Gears 180 Degrees / Positive Fourth Gears / Fourth Gears 180 Degrees / Fifth Gears 90 Degrees / Fifth Gears 180 Degrees Package Includes: 1 x Folding Sofa Hinge Note: 1. Please allow 1-2cm errors due to manual measurement. Ensure you are comfortable with this before ordering. 2. Due to differences in monitor displays, the actual color of the item may vary from the picture.