These are no ordinary bicycle tubes. These extra strong inner tubes stop flats for 2 years because there is Slime inside. Extra strong because there s Slime inside. Instantly seals tread area punctures up to 1/8” (3 mm) in size Seals multiple punctures repeatedly Non-toxic and non-flammable Cleans up with water Tube sizes and valve types available for nearly every type of bike. Works in bicycles wheelbarrows wheelchairs jogging strollers snow blowers and much more. 24 x 1.75-2.125