Pumpin' Pal Super Shields are simply the best designed breast pumping flanges on the market today. The oval design of the nipple area creates Better Flow of milk and allows ducts to drain faster and more efficiently. The Angle of the Super Shield allows mom to sit in a much more comfortable position with improved posture. The Ripple Design on the bell of the Super Shields moves the suction area away from the nipple and places it in a much less sensitive area on the breast, reducing nipple trauma and tissue abrasions. The overall design aids in the reduction of plugged ducts and mastitis.These flanges can be used in major brands of pumps----(Medela, Ameda, Lansinoh, Bailey, Rumble Tough), some as a replacement and some as an insert. The Super Shields come highly recommended by Lactation Consultants and are featured in current breast feeding books as an answer for moms to improve their milk output and comfort with pumping. An absolute must have for all pumping moms. The set comes with a pair of all three sizes a mom will need because her body will change throughout the time she is pumping and throughout the day as well. Having the set of all 3 sizes assures mom she has what she needs when she needs it and is priced more economically than when purchased separately.