Thanks to patented all-metal valves, Rene Herse TPU tubes don't suffer from mysterious leaks that occur when metal valve cores are screwed into plastic valve stems. The stems of Rene Herse TPU tubes don't have threads, which you'll appreciate if you use a pump with a press-on head. (The valve cores do have threads, so pumps with threaded hoses work fine, too.) We resisted the temptation to set new records as far as light weight is concerned. Instead, we use slightly thicker material to greatly increase the resistance to puncture and pinch flats. As so often, adding a few grams or material in the right places brings an outsize improvement in durability. And Rene Herse tubes are still superlight: The version for racing tires up to 32 mm wide weighs just 32 g. The biggest tubes, for tires up to 60 mm wide, comes in at 63 g. Everything about Rene Herse TPU tubes has been optimized based on the experience gained in thousands of miles of real-world testing. Advantages: - Low rolling resistance: as fast as ultra-thin latex tubes; faster than butyl and tubeless - Ultra-light weight: 1/4 of standard butyl tubes; 1/3 of ultralight butyl tubes - Tiny packing volume: 1/4 of standard butyl tubes - Greater durability: significantly greater puncture and pinch-flat resistance than butyl tubes - Superb air retention: patented all-metal valves eliminate mysterious leaks that plague many TPU tubes There's much to like about the new TPU tubes...