The Product that Started a Tubeless Revolution Inside this simple bottle is a product that changed cycling. Today's tubeless systems rely on the lighter, more reliable, self-sealing performance of Stan's Tire Sealant. Just two ounces of Stan's in a converted standard tire or tubeless tire can repair punctures up to 1/4-inch almost instantly to keep you rolling. Longer-lasting Stan's Tire Sealant is formulated to stay liquid in tires with even thin casings for up to seven months.