20Pcs Watch Mainspring Winder Tool Repairing Copper Composite Wooden Box Parts. Watch mainspring winder tools including 20 different model, suitable for most watch mainspring of the market. High precise watch mainspring winder design, suitable for professional watch repairing workers to use. About 20.5cm / 8.1in of the length, 13.8cm / 5.4in width and 6cm /…