Mesh truck covers are manufactured in our North Carolina plant. Our black mesh fabric is made out of a durable synthetic polypropylene. The slight stretch in the knitted cover allows for a snug fit. The open mesh knit construction provides 65% to 70% shade. Air can pass through the mesh cover, thereby resisting wind flap. The shade and air flow are due to the knitted construction which has a porosity/hole size of approximately 5 mm (this is slightly bigger than the "S" hook on a rubber tie strap or a bungee strap).