Size: ETRTO: 50/57-622 | 28/29 inches | wide Valve: car valve Material: The bicycle inner tube is extremely elastic and thus covers several tyre sizes Quality: quality and durability are the top priority for all Fischer products. That's why all bicycle tubes from Fischer are made of robust rubber Puncture proof: The bicycle inner tube contains a special gel, which serves for permanent sealing of small holes up to 3 mm in diameter