Extremely air-tight! Less air loss means having to inflate less. A unique rubber mixture makes it possible. Extremely reliable! Each SCHWALBE tube is individually examined twice at the factory to ensue air-tightness. Special quality control that prevents unpleasant surprises. Â Â Â 18-622Â Â -Â 28 x 3/4Â Â Â -Â 700 x 18CÂ Â Â 20-622Â Â Â -Â 28 x 3/4 Â Â Â -Â 700 x 20CÂ Â Â 22-622Â Â Â -Â 28 x 7/8Â Â Â -Â 700 x 22CÂ Â 23-622Â Â Â -Â 28 x 7/8Â Â - Â 700 x 23CÂ Â 25-622Â Â Â -Â 28 x 1.00Â Â -Â 700 x 25CÂ Â 22-630Â Â -Â 27 x 7/8Â Â 25-630 Â Â -Â 27 x 1.00Â