I took one nipple out of the package, intending to use it with a Pigeon Peristaltic nipple bottle, but it didn't seem to fit, so I didn't even try it. If you feel uncomfortable with it, please let me know, and I will dispose of the one I took out of the bag. I will fold the box and flatten the nipple for shipping. Although unused, please understand that this item has been stored at home and handled by a private individual. Thank you for your consideration.