All slime smart tubes are factory-filled with a precise volume of Slime tube sealant. Smart tubes instantly seek out and seal punctures as they occur, preventing flats repeatedly and continuously for up to two years. 20 inch tube with Schrader valveSeals tread area punctures up to 1/8 inch (3 mm) in sizeNon-toxic and non-flammableCleans up with waterSeals multiple punctures repeatedly for 2 yearsSelf healing tubePre-filled with "Slime" tire sealantSeals instantly