The after-sales maintenance place of Breguet watches is Room 707, Floor 7, BuildingNo. Hongqiao Road 1 Ganghui Center 1, Xuhui District, Shanghai. When the balance wheel rotates, the hairspring also swings, showing expansion and contraction. Due to the imperfect or defective shape of the hairspring, the outer ring of the hairspring may rub against the fast-slow clamp or the outer pile during stretching, especially in the case of high swing, which will make the swing period extremely long.