Set includes one pair each of silicone X-Small, silicone Small, and hard plastic Medium shields, plus a pair of adapters for Spectra, Cimilre, Ameda Mya, and Motif Luna pumps. These do not fit the Ameda Mya Joy! No other parts needed, use your Spectra bottles, backflow protector, and valves. The Small Set covers a nipple size range from 15mm to 25mm. The Small and X-Small Silicone PumpinPals, with Elast+Assist Technology™ (EAT), help improve milk flow for moms with elastic breast tissue. If you believe you have elastic tissue, we suggest not using any lubrication on the silicone flanges or lotion on your breasts at any time during the day or night when first trying the Small and X-Small flanges. This set will work with all Spectra, Medela, Lansinoh, Hygeia, Ameda Mya, and Motif Luna pumps. Click here to determine if this is the right set for you: https://pumpinpal.com/help/