ITEM NAME:100PCS Stainless Steel Watch Winder Winding Stem Extensions Extenders 0.9mm Product Description Feature: 100PCS stem extenders/extensions for repairing broken or extending watch crown stems; Perfect for self repairers and watchmakers; Material: Stainless Steel Length(approx.): 11.5mm Rod thin part diameter(approx.): 0.9mm Package Included: 100PCS* Wrist Watch Winding Stem Extensions If you have any uncertainty or feel confused about the item, please feel free to.100PCS Wrist Watch Winding Stem Extensions. 100PCS stem extenders/extensions for repairing broken or extending watch crown stems;. Material: Stainless Steel. We will try our best to reduce the risk of the custom duties.