Material: Electro-galvanized steel with a rust-proof zinc coating; 2.03 mm high-carbon steel wire, tensile strength, and non-deformable upon rebound. Dimensions: Hook-to-hook total length 165 mm (6 1/2 inches), cylinder 95 mm, outer diameter 16.5 mm (13/20 inches), 46 tightly wound turns; 90° offset hook head. Function: Solves problems such as lumbar sagging, slow rebound, and abnormal noise in reclining chairs, allowing the chair to return to its original position quickly. Installation: Pull out the old spring and clean the hanging holes; for the new spring, the large hook should face the fixed frame, and the small hook should face the movable rod; a light press will secure it. Packaging: Each pack contains 4 pieces., Manufacturer: AS Axis Spindleon