Produced by Stan's No Tube in the USA, Schwalbe Doc Blue Tubeless Preventive prevents and repairs all punctures (up to 6mm). It can be used to repair or seal all tubeless tyres. Schwalbe recommends using at least 60ml per MTB tyre, 30ml per Road tyre. The sealant works for about 2-7 months. Then it dries up and becomes a rubber layer. It becomes necessary to replace the sealant inside the tyre. This procedure can be repeated several times. It is not suitable for repairing larger damage such as cuts or burst tyres.