If you use your truck for work you will find that the best liner is simple plywood. Properly fitted to bottom,wheel wells,sides,front and endgate it lasts longer than the rest of the truck and when you remove it the box looks like new. It is also easy to attach things to, like a fire extinguisher bracket, tool boxe etc. I have detailed plans to build your own for superduty trucks. contact at ruhogwild2@telus.net