PRESTA VALVES: Available With 48mm Presta Valve, Non-Removeable Core. BUTYL RUBBER CONSTRUCTION: Ensures Excellent Air Retention and Durability. PUNCTURE RESISTANT: Thick Wall Construction Provides Protection Against Sharp Objects. PATCHABLE: Compatible With Butyl Tube Patch Kits. EXTENDED TUBE LIFE: Butyl Chemistry Engineered for Longer Life. FLEXIBLE FIT: Adapts Well Under High Pressure and Heavy Loads. ECO-FRIENDLY PACKAGING: 100% recyclable packaging, so you can hit the trails with confidence, knowing you're minimizing your environmental footprint.