20x1 1/4 /1.75 (32/47-406/451) FV 42 mm 0181231 Continental 20" 32-406, 20 x 1 1/4 37-406, 20 x 1 3/8 40-406, 20 x 1.50 47-406, 20 x 1.75 37-440, 20 x 1 3/8, 500 A 37-451, 20 x 1 3/8 47-451, 20 x 1.75 x 2 The Compact 20" from CONTINENTAL You can't see it on bicycles at all, and yet every bicycle needs (at least) two of them: the inner tube. The inner tube must fit! You can see which size inner tube is the right one by looking at the sidewall of the vast majority of bicycle tires. The first two digits of the measurements indicate the width of the tire, the following digits the outer diameter of the tire in mm. The Compact 20" inner tubes are available in different widths for 20" outer tires. The Compact 20" has a 42 mm long Sclaverand valve. Width inch 1 1/4 , 1 3/8 , 1.50 , 1.75 , 1.75 x 2 ETRTO 32-406 , 37-406 , 37-440 , 37-451 , 40-406 , 47-406 , 47-451 Main color black Valve type French valve (SV) Type/kind Article Valve length 42.0 mm Wheel size 20 " Continental Article number: 692357 EAN code: 4019238556353 Supplier number: 0181231 Retail packaging: Yes