Pre-installed, no mess Liquid Sealant seals punctures for up to 2 years. Sealant will not dry or freeze. Instantly seals punctures up to 1/8" as your rider. Tube Weight - 300g Valve type & length: Schrader; 40mm with valve core cap Great for Mountain bike tires See tire sidewall for Max PSI – Do Not Overinflate Sealant inside seals most holes up to 1∕8 inch instantly while you ride Lasts the life of the tire Tube sealant will not freeze or dry out