This Frankford 11 foot octagonal aluminum market umbrella has a 1.5” diameter center pole and 1/8” square aluminum ribs with a silver mist coated frame. This umbrella has a pulley and pin system that makes this umbrella easy to use. The heavy duty 9 oz. marine grade fabric is constructed to withstand abuse from the sun all day without losing color or disintegrating. This quality umbrella will withstand years of commercial use compared to other umbrellas.