A Chevy / GMC Tonneau Top is a vinyl cover that perfectly fits over your Chevy’s / GMC’s exposed truck bed. Generally, Chevy / GMC Truck Bed Covers make use of snaps and rails to hold the material tight and secute especially on rough weather condition or high vehicle speed; although some also use Velcro and U-shaped channels.  Installing a Tonneau Cover is definitely one of the best, if not the best upgrades you could add up to your ride. Creating a more aerodynamic profile to your Chevy / GMC, Tonnea Covers also dramatically improves your fuel economy by reducing drag.