... -service 3.function: furniture,tool 4.free sample high quality extension springMaterial:stainless steel,carbon steel,alloy steel Applications: Automotive, medical ... be broken.The spring surface is creamy feel flexiblity uniform,line state information,good heat resistance.Size:dia:.0.1mm-2 ... lead time: within 7 days delivery time: 15-20 days extension spring with hooks in hardware