Extang Classic Platinum Toolbox Tonneau Covers fit standard 18-20 inch deep tool boxes. An included adjustable sealing system easily bridges the tool box to Tonneau gap for a perfect fit. The L-channel design also provides for water drainage. Extang Classic Platinum Tonneau Covers feature a heavy-duty vinyl tarp with reinforced edges and corners, anodized rails with metal corners and stainless steel snaps. The Platinum cover features an Extang exclusive, 4-way adjustable, all-climate Tonneau design. The snaps may be adjusted for a looser or tighter fit. In addition, the TuffKlamps provide two bow heights with the high setting for maximum water shedding in harsh weather, and for improved gas mileage, low setting for sporty good looks and cold weather Tonneau attachment. The secret to our tonneau’s great looks and fit is a perfectly sewn tight fitting tarp with special anti-curl corners. Thick vinyl binding around the tarp perimeter provides a long and durable tarp life. Snaps and corners are backed with thick polymer forcing the corners and edges to lie smooth and look good in any weather. Extang's Monster Bows quickly spring on and off with no tools. It is fast and easily done with one hand. The tarp easily rolls up to provide full length use of open truck bed. The Classic Platinum Toolbox carries Extang’s Maximum Strength Warranty offering lifetime coverage on the frame and components and 10 years on the tarp assembly. Extang has been manufacturing America’s number one selling pickup truck bed tonneau covers since 1982 which are made in the USA.