From the award winning Swiss brand Medela, the Personal Fit? Nipple Shield will aid in pumping and will protect sore or cracked nipples. ? Box includes 2 BPA-free shields. ? For use while pumping only. ? Reusable. ? Select the size that works best for you. ? Compatible with Medela breast pumps. ? Available sizes: ? Small = 21 mm. ? Medium = 24 mm. ? Large = 27 mm. ? X-Large = 30 mm. ? XX-Large = 36mm.