The AirStop has a butyl construction that holds air better than standard tubes and is more resistant to punctures. Features: .9mm thick butyl construction for reliable performance in all applications Specs: Color: Black ISO Width (mm): 35 mm , 36 mm , 37 mm , 38 mm , 39 mm , 40 mm , 41 mm , 42 mm , 43 mm , 44 mm , 45 mm , 46 mm , 47 mm Labeled Size: 700 x 35-47 Tube Compound: Butyl Valve: Standard Schrader Valve Core: Removable Wall Thickess: .9 mm Weight: 166 g