I make herbed oils each year for Christmas gifts. I have always had a problem with sealing the bottles after they are opened to insert herbs. The plastic inserts in the bottles do not seal after they are opened. This year i looked for corks to seal the bottles and found this website. Once I figured out what size to get (math involved), I ordered 25. They came really fast and I prayed I did the math correctly. Well, I was able to completely remove the plastic inserts and the corks fit perfectly. I now have a complete seal and no chance of leakage while wrapping the bottles of oil. I will be ordering these every year. Problem solved and very cost effectively.