Feature: 1. It is made of butyl rubber material with greatly improved airtightness, temperature resistance, delay aging and longer service life. 2. With schrader air valve, it is no need to replace the valve core, which is convenient to use. 3. The butyl rubber tire inner tube can absorb the vibration of uneven roads to ensure the comfort and safety of driving. 4. Easy to install, you can easily replace the old inner tube of the tire in a short time, saving time and efficient. 5. It widly fit 12 / 14 / 16 / 18 inch wheel, width between 1.75‑2.125inch tires, suitable for replace the inner tubes of road mountain bikes. Specification: Item Type: Bicycle Inner Tubes Material: Butyl Rubber Product Color: As Pictures Shown Product Weight: Approx. 145-180g / 5.1-6.3oz Valve Type: Schrader Valve Maximum Air Pressure: 8 Bar Standard Pressure: 20. Package List: 1 x Bike Inner Tubes Note: 1. Check the tire to see if there are any bad factors in the steel rim.2. Correctly install the valve of the inner tube and expose the steel ring vertically.3. Ensure that the inner tube is not pinched between the outer tube and the steel rim.4. Inflate some air first to check whether the tire is pinched.5. Inflation of the inner tube should meet the standard air pressure (see the words on the sidewall of the outer tire).