AERON/TPU offers the ideal inner tube technology for mountain bikers with the best compromise between lightness, puncture resistance, and low rolling resistance. Specific models will offer you the perfect soul for your favorite mountain biking discipline, depending on the terrain or riding style. Main advantages of Protection Level 2: Extremely low rolling resistance, super lightweight, and puncture-resistant – for racing and performance use. Up to 82% lighter than a comparable butyl tube – absolute world-class! Significantly better rolling properties than butyl, which also makes it suitable for performance driving and racing. Record-breaking small package size. Also ideal as a spare tube for tubeless riders, as it fits into even the smallest tool pouch or jersey pocket. Multilayer construction. Aluminum valve stem. Specifications Size: 27.5"-29" Tire width: 1.7-2.5" Valve type/length: SV42 mm Weight: 40 g Weight savings: 82% Protection level: 2 Brake type: Suitable only for disc brakes