2x Kayak Cart Dolly 10" Air Wheels Replacement Tires for Hand Truck Dolly Cart Wheel Kayak Hub 10(in) Diameter, 4(in) Width 5/8(in) ID Ball Bearing Hub, Rated for 300 lb. loads Tube: Nylon, Rating: 2 Ply, Size: 4.10 / 3.50 - 4 For carts, Dollys, kayak cart, Not for highway applications. 300-lb. plastic hubs are great - they do not rust built to last