Product details:

These 12-inch large, airless wheels will never go flat, and are designed to roll over rough terrain smoothly. Made of strong plastic. Add versatility to your Wilderness Systems Heavy Duty Kayak Cart with Beach Wheels for when the going gets rough, or you need the extra weight load capacity. Airless wheels that will never go flat Designed to roll over rough terrain smoothly 450lb carrying capacity 12" diameter, 3.5" wide Set of two wheels only - no additional hardware is included