[Widely used for REAR WHEEL]-Attention : Only rear wheels can be used. If you are looking for inner tubes for front wheel, check at stores we have 8.5 inch 50 or 75-6.1 tubes with straight valve that can be used for front wheel. [THICKENED and PUNCTURE-RESISTANT] - inner tyre adopts the thickened design, 2pcs 8.5 inch thickened inner tubes can be used on the rear wheels. tires are 1.9mm thick, which are stronger than the tires and have better puncture resistance. It can be use for a long time. [HIGH-QUALITY MATERIAL] - Electric scooter inner tube is made of high quality butyl rubber material, which has good thermal stability and air tightness, and is also environmentally friendly, non-toxic and harmless. [EXTENDED VALVE]- In order to easier to inflate the inner tube, we have extended the valve of the inner tube. The extended valve can inflate the inner tube more efficiently. At the same time, the curved mouth valve nozzle plays a better role in protecting the inner tube, so ' worry the inner tube is easy to puncture. [EASY INSTALLATION] - To make changing the inner tire more convenient, we have equipped 2pcs Colour:black Material:rubber Package Contents: 2 x inner tubes 2 x wrenches Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is 1-3cm.