Marathon Flat Free Quick-Seal Replacement Inner Tube - 18x8.50-8"/20x8.00-8" - Pre-filled with Flat Free Tire Sealant For an 18x8.50-8" or 20x8.00-8" Tire Repair your flat tire, seal punctures and prevent future leaks-all with one tube Sealant will seal tube punctures up to 1/8" Tube is pre-filled with Flat Free Tire Sealant Sealant will not free or dry Repair your flat tire, seal punctures, and prevent future leaks - all with one tube For an 18x8.50-8" or 20x8.00-8" Tire Repair your flat tire, seal punctures and prevent future leaks-all with one tube Sealant will seal tube punctures up to 1/8" Tube is pre-filled with Flat Free Tire Sealant Sealant is Environmentally Friendly-it will not free or dry