The spring body is 20mm long, with an outer diameter of 8.7mm and a wire diameter of 1.4mm. It is suitable for rods with a maximum diameter of 5.5mm and also for rods with smaller diameters. Made of 304 stainless steel, it has good elasticity and corrosion resistance and is durable. This spring is designed for traditional British door mailboxes (Letter Plate), ensuring that the mailbox door opens and closes naturally and smoothly, effectively preventing wind from blowing it open or noise interference. Suitable for repairing and replacing old mailbox springs after they are loose or broken, and restoring their original functions. Each package contains 4 springs, which is convenient for double door replacement or spare., Manufacturer: ECSiNG