These Mavic tubes are a perfect match for Mavic's exceptional tires and will also work with any 700x21-25 clincher tire. Mavic Road tubes have a pump friendly smooth valve stem and are a moderately light 81 grams. The valve core is non-removable so these will only work with fill-tube type extenders. But you won't have to worry about leaks due to a loose valve core! 48mm length stem works on rim profiles up to about 30mm.