For use with all Medela breastpumps. Use this to replace your original breastpump parts or to keep an extra set at work. Includes: Standard size (24mm) 1-piece breast shield includes connector - 1 each Preassembled with Valve (x1) and Membrane (x1) Note: This item is sold individually as a single unit set. If your requirement is for a pair, please order quantity 2 each. For other Medela breast shield sizes (21 mm, 24 mm, 27 mm, 30 mm, and 36 mm), check listings under Parts and Spares. Breast shields in other sizes are not available in one-piece construction - breast shields and connectors are sold separately.