Marathon Easy Fit 4.00-6 Pneumatic Wheel Assembly for Residential Wheelbarrow Perfect replacement for 4 Cubic Foot Wheelbarrows and other Residential Wheelbarrows & Carts 4.00x6 (3.50/2.50-8) - 13.2" pneumatic, tube-type tire with ribbed tread Fits 1.75", 3" or 6" hub lengths - adjustable with included adapter kit 5/8" Nylon Bushings installed in black steel wheel 300 load capacity / Not for highway use