For sale is a WeatherTech AlloyCover that was on my 2020 GMC 2500. Best I can tell, it should fit a 2020-2024 GMC 2500/3500 standard bed. It is in excellent shape. Truck it was on was always kept in garage. Comes with cover, rails, brackets. Installation instructions are on Weathertech website. These go for over $1000. I have had several different bed covers and this one was the best I had.