This listing is for a PAIR of quality Impac Inner tubes by Schwalbe These will fit 18" wheeled bikes running tyres from 1.75- 2.25 Standard 35mm long Schrader valve Reinforced dual thickness tube valve interface to prevent punctures Light weight butyl rubber construction Suitable replacement tube to fit the following tyre sizes: 18 x 1.75 (47-355) 18 x 2.00 (50-355) 18 x 2.10 (54-355) 18 x 2.25 (57-355) No need to wait around for the courier as they conveniently packed for FREE LETTERBOX DELIVERY! PLEASE NOTE: To keep the price low, this tube may be shipped without the original manufacturers box.