1.high quality raw material 2.easy for installation 3.surface treatmet: zinc,nickle and etc 1.Material: made from 70# carbon and steel wire,not easy to deformation after the heat treament,with high quality.2. Finishing: Nickel-plated, chrome-plated, zinc plated, gold-plated and etc.3.Varieties:diverse selection of springs can meet your different request,can be customized to your samples.56mm53. ...