Made from FDA-approved silicone, Crew's high-quality spout covers check a couple of important boxes. First, they prevent unwanted debris from entering your liquid creations. Second, they help to prevent oxidation and increase the shelf-life of perishable ingredients (e.g., olive oils). They're compatible with most standard steel pourers and fit snug as a bug onto Pour Boy® Pour Spouts. We recommend hand-washing this item to avoid losing them in the dishwasher.