Retrax 10421 ONE Retractable Truck Bed Cover | fits Chevy & GMC 5.8' Bed (07-13) Opens and closes easily with our exclusive use of sealed ball bearings Low Profile Design - Our Front Canister Cover Remains Flush With the Rolling Cover Low profile design - Our front canister cover remains flush with the rolling cover Key lockable in any position - Secure your valuable cargo Unlimited Hauling Flexibility. Great For 5th Wheel Hauling. Improves Mileage By Up To 10 Percent Unlimited hauling flexibility - Great for 5th wheel towing. Improves mileage by up to 10%. UV Protected; No Fading, No Maintenance