The Stans Tubeless Sealant is the best choice for providing reliable puncture sealant performance for all tubeless road, gravel, and mountain bike tyres. Sealing punctures up to 6.5mm, the Stans Tubeless Sealant works in temperatures down to -20ºF and injects directly through removable tubeless valves for easy application. Compatible with all tubeless tyres, it keeps you riding longer without flats. Buy your bike sealant at Halfords, the UK's largest bike accessories retailer.