INCLUDES - 1 pc Hammock Chair Spring, 1 pc Swivel Snap Hardware, and 1 pc Bearing. The spring and u-pin plugs are made of steel, surface treated with baking process, anti-rust, corrosion-resistant. Upgrade Kit Bearing - BEARING made of steel, has great wear resistance, high temperature resistance and high hardness. It can effectively increase lubrication and reduce noise. The spring can absorb the vibration when shaking, play a buffering role, increase the service life of the chair, and make it more comfortable when shaking. WIDE APPLICATION - For use with almost all hanging chairs, egg chairs, porch swings, freestanding swings, hammocks, and hammock chairs. The spring can meet the daily use of most families, which is consistent with the load-bearing capacity of ordinary egg hanging chairs. EASY TO USE - You can refer to the picture for the installation sequence, the clevis pin passes through the support and connects to the spring. You can install it or replace the existing ones in minutes.