Size: 32mm (Regular valve). Fits 20" x3.5/4.0" tire tube. compatible with Road bike /Mountain bike Tire ( ETRTO : 90-406/100-406 ) bicycle tire tubes.
Installation Precautions: Please check the side of your tire for the tire size your bike uses.
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.
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.
