Boon SNUG Spouts are very convenient, turning any old regular cup into a sippy cup! SNUG silicone sippy lids fit over any regular cup with a 2.5''-3.75'' diameter and instantly prevent that cup from spewing its contents when knocked over or tossed off a high chair. Hooray for cleanliness. ExpirationThis product has no expiration date or the manufacturer has not provided an expiration date.