Dr sludge self sealing inner 20 tubenow pre filled into inner tubes in the correct dosage featuresprevents flat tyres seals punctures instantly up to 3mm diameter works time after time water based with anti corrosion properties and is completely harmless inner tube and tyre will not stick together will not dry out regardless of outside temperatures every inner tube is individually tested before leaving the factory buydr sludge wheels tyresfrom chain reaction cycles the worlds largest onl