I replaced my tunnel cover and use the truck cap. I bought this truck brand new with the tunnel cover. It’s not even a year old yet selling it for 625. It’s off of a 2024 Silverado 2500 HD The measurements are in the pictures it’s for the extra long box. I believe it’s almost 6 .10 Standard length for the 2500s takes about 20 minutes to install and it keeps the box dry 416-828-5858. If you want I can help you put it on.