Feature:1. PREMIUM MATERIAL: The inner tube is made of high quality butyl rubber, which has good airtightness and heat resistance. The air nozzles are all highly airtight, stable and durable.2. LONG LIFE: The bike inner tube has excellent air retention and does not need to be pumped up for six months under normal use, saving time and avoiding the hassle of frequent pumping.3. APPLICABLE: The inner tube is suitable for replacing mountain bike inner tubes, 29in bike inner tubes fit 29in wheels.4. NOTICE: When removing or installing the inner tube, do not use installation tools to avoid puncturing the inner tube.5. QUALITY ASSURANCE: After explosion proof and inflation tests, our quality control can give you peace of mind. Long service life, not easy to leak and damage.Specification:Item Type: Bike Inner TubesMaterial: Butyl RubberSize: Circumference: Approx. 29inWidth: Approx. 1.9/2.3inAir Nozzle Specification: A/V (US Nozzle)Features: Puncture Resistant, Airtight Performance is Strong Package List:1 x Bike Inner TubeNote:1. Check how many inches the bike tyre is before buying, between 1.9/2.3in tyre widths. 2. Manual measurement please allow some errors.