Spring Specification 5FT,6FT,7FT,8FT,10FT: Dia22xLength135x3.0x28N 12FT,13FT,14FT,15FT: Dia22xLength165x3.0x40N 16FT:Dia24xLength180x3.2x40N Springs Feature 1.Galvanised Spring, surface is very smoothly. 100% assure quality is very very strong. 2.High Tensile and Durable. 3.Galvanised springs are stretch-resistant for the utmost bounce and long-lasting enjoyment. 4.Weather Resistant and Anti-Rust. 3.Processing, finished spring are highly strictly controlled and tested. 4.Top quality,Factory price.