Tyres size 26" x 34 -44c presta valve This self seal inner-tube is filled with with a special formulated Goo that coates the inside of the tube. This helps prevent punctures up to 3mm in the main tread area of the tyre USEFUL TIPS Ensure wheel is turned several times prior to riding. This will allow the Goo to coat the inside of the tube more evenly Always remember to ensure there are no objects in the tyre when fitting the tube that are likely to cause punctures Goo will not protect against sidewall punctures or large rips