TANNUS ARMOUR INSERT 20x2.0-2.5Tannus Armour is a special insert that wraps around your tube providing up to 15mm of puncture protection in addition to other benefits In the unlikely event you do get a flat tire, you can still ride for a limited period of time with less risk of rim damage *excludes fat tire sizes* The Tannus Armour sidewall helps stabilize your tires on corners and cushion the ride for more comfort Use of Tannus Armour requires use of a smaller tube, see links tab