Threadless Titanium Replacement Top - Flat Opal0.45mm Threadless Shaft. Compatible with 0.5mm Threadless JewelryChange up the look of your jewelry quickly and easilyHundreds of color and size combinations to choose fromHow to Use Threadless Jewelry:Threadless jewelry uses tension between the end and the shaft to fit and stay together. The end has an insertion pin which is slightly bent when inserted into a straight shaft. This slight bend of the pin against the straight shaft creates a spring tension, holding the end securely in place.Follow the instructions below to secure the threadless end into the threadless shaft Insert the pin one-third to halfway into the shaft. Hand-bend slightly the insertion pin against the shaft. Push the end into the shaft and test the fit. Adjusting the Fit: If it is too tight, take some of the bend out of the pin and try again. Remember, adjust slightly and then try again.