Adjustable: Angle lifting rod adjusting hinge bracket. Material: high quality steel iron, rust resistance,sturdy, durable and practical. Application: Suitable for lifting sofa backrest, folding bed and other folding furniture Features: This lifting hinge adjustable connectors for connecting the backrest and seat board,bed frame and the bed etc. Easy to Install: According to the specifications of the hole, set the size, and then fix with screws. Specification: Material: Iron Size Chart: 7 Gears Hinge Length: 28.5cm /11.22inch Total Length: 18cm/7.09inch 10 Gear Hinge Length:39.8cm /15.67inch Total Length: 23.8cm /9.37inch Package Includes: 2 Lifting Rod Hinge(Left and Right) Note: Please allow slightly errors due to manual measurement and different monitors.