This is a part that came with a betta fish feeding bottle. It has been stored without being used. I hope someone who needs it will use it. How to use: Open the air vent at the base of the nipple and the hole at the tip of the nipple (round hole/cross cut) by gently poking them with the heart pin. This will make the milk flow smoothly. * Please be careful not to tear the nipple when using. * Please do not let the baby hold it under any circumstances.