These are Replacement Screw Balls for any Externally Threaded Shaft We have 3 sizes to choose from and 5 diameters ( 2mm, 3mm, 4mm, 5mm, 6mm) and each size is sold in a 6 pack. Each pack contains only one size, so please select carefully as these are not mixed bags. Perfect for piercing professionals or people who sometimes misplace their beads. Shipping and Returns We are a U.S. based seller and all of our products are shipped from the United States. You can return any product within 30 days from purchase date. We Care And Will Reply Within 24-48 Hrs!