Frame: hard materials, steel is strong, consistent with the GB/T3324 standard, corrosion, insects not deforming. Sponge: high-density foam, high bounce foam sponge, with moderate softness, good resilience, flexible. Sponges are a modern aesthetic and ergonomic principles, and ride comfort. Finish: leather (optional green leather, domestic) make the guests look like buy! "Packing instructions": according to the actual needs of customers packing "installation difficulty": easy to install