Michelin Airstop A3 inner tube A Michelin bicycle inner tube usually consists of butyl. Butyl is a very elastic and at the same time airtight synthetic rubber. Due to its high elasticity, the Michelin inner tube is suitable for covering a wide range of tire sizes. Specifications: Color: black Gender: unisex Material: rubber Inch size: 27 / 28 Valve type: Dutch valve Valve length: 40 mm Valve diameter: 7.7 mm Maximum valve pressure: 6 bar Weight: 220 grams Suitable for inch size: 27 x 1 ¼ 28 x 1.35 28 x 1.40 28 x 1.50 28 x 1.60 28 x 1.625 28 x 1.75 28 x 1 5/8 x 1 3/8 28 x 1 5/8 x 1 ½ 28 x 1 ½ Suitable for ETRTO size: 35-622 37-622 40-622 42-622 44-622 47-622 32-630 40-635 Suitable for French size: 700 x 35C 700 x 38B 700 x 38C 700 x 40C 700 x 42C 700 x 45C