Hose Michelin MICHELIN hoses are made from butyl rubber, which gives them very low gas permeability and elastic behavior even at low temperatures. Butyl tubing has good resistance to acids and bases as well as very good weather and ozone resistance.    Valve type: TR4 Valve straight Wall thickness: 1.4mm Suitable for the following tire sizes: 2.50-21 2.75-21 3.00-21 MH90-21 80 / 90-21 80 / 100-21 90 / 90-21 90 / 100-21