LET’S DRINK TO THIS! Boon SNUG Silicone Sippy Spout Lids stretch easily over any regular cup with a diameter 2.5?3.75 inches to turn it into a sippy cup. It instantly helps prevent the cup from spewing its contents when knocked over or tossed off of a high chair. These Boon sippy lids are great for kids old enough to drink from a sippy cup but not quite ready for an open cup. Place these sippy cup accessories in the top rack of your dishwasher to clean away all the goo.