I'm selling these as I no longer need them. They are all made of plastic. The two long ones on the left are several years old. The two shorter ones on the right were just purchased and have only been used for about 4 months. All of them have size L nipples attached, but if you don't need them, please let me know. The size L nipples have also only been used for about 3 months, so they should still be usable, but if you're concerned, you can discard them. There are slight traces of the detergent used in the last wash. These are used items, so please check the photos and purchase with your understanding.