Slime Self-Sealing Smart Tubes are pre-installed with Slime Sealant, providing maximum puncture protection. Slime Tube Sealant prevents and repairs flat tires caused by puncturing objects up to 1/8-inch (3mm) in diameter. That means longer distances, faster times, and no flat tires. Slime Self-Sealing tubes install like regular bike tubes and repeatedly seal punctures for up to two years. Designed to seal tread area punctures.