For the 2014-2018 Chevrolet Silverado 1500 and GMC Sierra 1500 and the 2015-2019 Silverado and Sierra 2500HD/3500HD, this Sentry CT fits the 6'7" box (78.9") that GM sells as its 6'6" standard box. It also covers the 2019 Silverado 1500 LD (also called Legacy) and Sierra 1500 Limited, which kept the 2018 body. As a hard roll-up, it puts interlocking aluminum slats under an RTxTechWeave canvas top and still rolls forward to the cab when you need the whole bed. Where the tailgate has a key lock, the latches stay out of reach until it is unlocked and opened. Closed and latched, it carries 400 lb of evenly distributed weight. It clamps on; no drilling is needed on most trucks. TruXedo covers it for five years.