Very high-quality Mountain Bike inner-tubes prefilled with Joe's Super Sealant- the world's leading tire sealant, prevents flats by instantly sealing punctures in the tread area of the tire up to 3mm. 220gram inner-tubes prefilled with 120 grams Joe's Super Sealant (total 340 grams for 26" tube).
Tips:
If you get a puncture, always SPIN the wheel to distribute the sealant.
If spinning does not work, find the hole, in turn, the wheel so the hole will face the ground.