TonnoSport 22020139 Roll-Up Cover for Chevy/GMC Full Size Stepside Box (Bolt On) Attachment Friendly - Compatible with bed rails, bed caps, tailgate protectors, as well as drop-in under-the-rail and spray-on bed liners Quick clamp-on installation Lockable - protects your cargo Pays for itself in the first year of ownership by boosting your gas mileage as much as 10 percent No need to remove - complete bed usage when cover is open