SIZE:32mm Schrader (Regular valves). Fits 20" x 2.125"/2.40'' tire tubes. High Quality:The bike tube is made from premium butyl rubber.It has the advantages of good sealing performance, ozone resistance, aging resistance, shock absorption, electrical insulation. Easy Installation:Installation is quick and easy. Please follow inflation guide when airing a tire from a complete flat. Save time and effort, replace the old tube in a few minutes. Important Note:When changing a bicycle inner tube, be sure to add a little air before installing it. This gives it form so it doesn't get twisted or bunch up which may cause a pinch flat. Inspect for an even bead of the tire to the rim on both sides. Comfortable and Safe:After replacing the butyl rubber tube, it absorbs the impact on the uneven road surface, making riding more comfortable and safe. Tip: Before installing the inner tube, please put the inner tube into the water for inspection, if there are bubbles, it means that it has been damaged, you can contact us. Check the valve position to ensure that the installation direction is correct. Note: The inflatable inner tube should avoid puncture by sharp objects. 2-pcs 20x2.125/2.40 AV32mm Schrader Valve bike tubes