Suitable for connecting armrests and seats, backrests and seats, pillows and backrests, armrests and backrests, bed frames and bed surfaces, etc.By operating the gears, you can change armrests, sides, pillows, seats and bed surfaces.Angle adjustment, concealed installation security, gear opening and closing card design, multiple angles, multiple gears.Size: 23 x 7 cm .Function: Used to connect the back of the sofa and the back of the seat. The height of the backrest of the sofa can be adjusted to change it from a sofa to a bed.Suitable for connecting armrests and seats, backrests and seats, pillows and backrests, armrests and backrests, bed frames and bed surfaces, etc. By operating the gears, you can change the armrests, sides, pillows, seats and bed surfaces.Angle adjustment, hidden installation security, open and close card design, multiple angles, multiple gears.Material: IronSize: about 23 x 7 cm.Color: black.Adjustable: 3 positions.Uses: sofas, sofa beds and other furniture.Package content :1 pair of adjustable sofa hingesMounting screwsNotes:1. Due to manual measurement, please allow 1-10mm error.2. The color may be different.