BMX / small diameter car tires ensure driving power transmission on the road while reducing rolling resistance. The "bristle knob" is located in key areas that adapt to rider input and creates grip when needed. UTC Rubber Compound Cylex Casing Kevlar Beads Recommended Air Pressure: 240 - 450 kPa / 35 - 65 PSI / 2.4 - 4.5 BAR Weight: 8.3 oz (20 x 1.1/8), 9.8 oz (20 x 1.3/8) Product color and size may differ from the actual product depending on your display type. Product specifications, logo design, etc. may be subject to change for product improvement. We also cannot answer measurements or personal fit that the manufacturer does not announce. Please be aware of