These are bike  tube replacement not for standard wheelchair wheels. these are AV10 tubes designed to fit the following sizes. 

40 - 507 / 24 x 1.50

47 - 507 / 24 x 1.75

50 - 507 / 24 x 2

56 -507 / 24 x 2.10

57-507 / 24 x 2.25

62 - 507 / 24 x 2.40

Why Schwalbe Tubes

Besides the quality of the ingredients, the purity of the rubber compound is decisive for the quality of the tube. Before extrusion, the basic material is forced through a total of seven filters under enormous pressure. All tubes are inserted and inflated into a mold for the vulcanization process. Only this ensures an even wall thickness and high air retention.