Maymom Breast Shield (21 mm, 1-Piece) is available in Breast Pads & Shields

One-Piece Breastshield (21 mm internal diameter, specially designed for Spectra Pumps) , 1 Valves, 1 Membranes; Compatible with Spectra pumps S1, S2, M1, Spectra 9 having the back-flow protector.

Can be steam sterilized, microwave sterilized or sterilized in boiling water.

Made from BPA free and DEHP-free material

Retail poly-bag packed; sealed by the manufacturer, Maymom

You need to purchase a narrow neck to wide neck adapter (B0040QHFVM) if you wish to use wide neck Spectra or Avent bottles.