everything and anything. From gravel to a 1500 pound Eaton transmission that wanted to tumble all over the place no matter how I strapped it down....pretty much nothing has done any damage to the liner. I've had gasoline, diesel, engine and hydraulic oil spills, not to mention the brutal AZ sun and it just keeps on taking the beating. I will never own anything but a spray-in and if you go that route I'd definitely have the liner on top of the rails of the bed as well. Makes it easier to load or rest items on the top rails of the bed and not worry about scratching the paint. The one thing I wish i had gotten was the sealant that maintains the shine of the original application but without it it just fades to a mat black rather than glossy. Worth the money IMHO.
