Mascot dog leash spring mainly used in the pull-out and recovery of dog leash/rope. Our leash spring material is made of carbon steel, the strength is soft and continuous, and this spring has a long life lifecycle which can reach 50000-100000 times. And also it relates to the material and thickness. The production process of mascot dog leash spring is mature, stable, efficient and cost-effective.Welcome to contact us with your drawing sheet or data( spring thickness, width, working length, inner diameter, outside diameter) . we are pleased to provide you with cost effective products.