Virtually impossible to get a flat Fits most wheelbarrows and small lawn and garden equipment. Compatible Replacement Sizes include: 4.80/4.00-8" ( 15-16” diameter), 3.50/2.50-8" (13” diameter), and 4.00-6" (13” diameter) - 5/8" Ball bearings (please check your existing hub Size for proper fit) Polyurethane construction won't break down from UV and weather exposure Ideal for wheelbarrows, carts, and small equipment Pressed and sealed ball bearings for smooth operation