This inner tube is made of isobutylene isoprene rubber, which is better in airtightness, elastic damping and aging resistance than natural rubber. NOT recapHeavy duty inner tube with TR87 bent valve stem, max inflation is 30 PSI. Inflate with hand pump only4.10 3.50 - 4 Inch Inner Tube Works With Hand Carts, Carts, Yard Cart, Yard Cart, Lawn Cart, Utility Cart, Flat Carts, Lawn Mowers , small tractors, wheelbarrows, garden trailers, cart carts, wagons, generators, snow blowers and most 410 / 350-4 wheel applicationsPerfect fit for 4.10/3.50-4 inch TIRES/WHEELS: Replacement tubes for 4.10/3.50-4 tires/wheels (10 inch outer diameter). also measured in 4.10 3.50-4, 410/350-4, 3.5-4 4, 4.1/3.5 4, 4.10 3.50 4, 4.10 3.50-4 , 4.10 / 3.50-4, 4.10/3.50-4 inch, 4.10x3.50 -4 inchCUSTOMER SATISFACTION: Before installation, check whether the inner tubes are completely sealed by immersing them in water, if there are bubbles, they are already damaged.