This is rubber matting used for a workshop floor or something. I use it for my work trailer floor. You can get it at hardware stores- cut to length, cheep.

I used it on the back side of my battery after i found deep grooves in the battery case from the rear fender battery holder tray after only 200 miles or so. Thought i'd share.

Here you can see the imprint from the fender.(that would otherwise be in my battery)