Based on the answers you gave to on the questionnaire, it appears you have very elastic skin. This condition can cause the nipple and areola to be drawn deep into the tunnel of the flange. When this happens, the milk ducts can be stretched so far they become very narrow and can actually cut off the flow of milk that your body is releasing. This can lead to clogged ducts and decreased production. This is known as Lactiferous Duct Dysmorpia.
The Small set contains the Small (pink) and X-Small (blue) pairs of Pumpin’ Pals, which are made of silicone. Clean silicone actually has a “sticky” feeling against your skin, which allows it to hold back your extra elastic skin from going too far down the tunnel. Keep in mind that the silicone needs to be kept clean in order for it to continue being “sticky” and keep holding that skin back. Build up of milk residue or lubricating oil, like coconut oil, will make them ineffective.
The Small set also comes with a hard Medium size pair of Pumpin’ Pals (green). Over time during your pumping journey, your breasts tend to change. This can be caused by many factors, including liquid intake. Many moms find the will not need to drink as much water to maintain their necessary milk output, and that can lessen the elasticity of the skin, and the silicone may not be needed any longer. These moms may find the Medium flanges more comfortable and easier to use at that point.