Tubeless must have
Using on tubeless mtb wheels and working great. Kind of pricey for what they are, but you have to have them and they're well made so they should last. The only part likely to fail, the valve core, is replaceable. If I notice the valve seems sticky, remove it and peel off a bit of dried sealant and its good to go. I still keep extra cores just in case. If you don't know already, these are presta valves and won't fit in rims drilled for schrader valves. They also seal themselves using air pressure, so they don't have a spring in them.