General description This inner tube is made of isobutylene isoprene rubber, which offers superior air tightness, elastic damping, and aging resistance compared to natural rubber. It is a heavy-duty inner tube featuring a TR87 bent valve stem, with a maximum inflation pressure of 30 PSI. This product is designed for various applications including hand trucks, dollies, garden carts, yard wagons, lawn carts, utility carts, flatbed trucks, lawn mowers, small tractors, wheelbarrows, garden trailers, dolly carts, wagons, generators, and snow blowers. Technical specifications Size: 4.10/3.50-4 inch Outer diameter: 10 inches Maximum inflation: 30 PSI Material: Isobutylene isoprene rubber Usage Before installation, ensure the inner tubes are completely sealed by submerging them in water; if bubbles appear, the tubes are damaged. Inflate the inner tube using a hand pump only.