This add-on is to convert one set of straps to have curved ends. Curved ends are particularly useful to prevent the straps rubbing the case of the watch. Some watches require curved ends such as F.P. Journe and Ming due to the spring bar holes being located close to the watch.
If you are unsure whether your watch requires curved ends, please feel free to contact us.
NOTE: Curved ends do not mean the strap sits flush with the case. This would require a special proprietary insert that matches the case of the watch, which at this time, we are not able to produce.