This is actually heavy duty plastic used to protect the bottoms of telephone poles. Some might find it too thick but maybe you want something really tough under there?
Maybe you just really like orange.
Think heavy duty roll-up sled.
Don't ask where I got it
Size is 6' x 3.5' (72"x42") one side is smooth, other side has lengthwise ridges for strength.
FREE, you pay shipping. I have a FedEx account that gives me 40% off so shipping should not be too bad at all.
Detail of in and outside surface :
Showing the thickness a bit. It is actually thinner than this because it is rolled over a little bit on the edges :
In all of it's glory :
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