This pack features 2 breast shields that work with the Medela Magic InBra™ breast pump. Made from BPA-free materials, these comfortable breast shields come in 4 sizes (18 mm, 21 mm, 24 mm, 27 mm) and are designed to be compatible with Medela InBra™ breast pumps. Breast pumps sold separately. Features: - AUTHENTIC MEDELA REPLACEMENT PART: These breast shields are authentic Medela-manufactured replacement breast pump parts - COMPATIBILITY: For use only with Medela InBra™ breast pumps - MARKED FOR EASY MEASUREMENT: Each breast shield features markings to indicate amount of breastmilk pumped - SIZING OPTIONS: For maximum comfort and pumping efficiency, Medela offers four sizes of breast shields for Magic InBra™ breast pump - MADE WITHOUT BPA: Medela Breast Shields are made of BPA-free silicone