[Widely used for REAR WHEEL] - Attention please: These inner tubes are designed for rear wheels only. For front wheel inner tubes, please check our store for 8.5 inch 50/75-6.1 tubes with straight valve. [THICKENED & PUNCTURE-RESISTANT] - Our inner tubes feature a thickened design. These 2pcs 8.5 inch thickened inner tubes are suitable for rear wheels. With a thickness of 1.9mm, they offer enhanced strength and improved puncture resistance for longer service life. [HIGH-QUALITY MATERIAL] - Made from high-quality butyl rubber, these electric scooter inner tubes provide excellent thermal stability and air tightness. The material is environmentally friendly, non-toxic, and safe. [EXTENDED VALVE] - Designed with an extended valve for easier and more efficient inflation. The curved valve stem helps protect the inner tube during use, reducing the risk of damage. [EASY INSTALLATION] - For convenient replacement, we include 2 wrenches. Color: black. Material: rubber. Package Contents: 2 x inner tubes, 2 x wrenches. Light reflection and display differences may cause slight color variation between the image and actual item. Measurement may vary by +/- 1-3cm.