Where to go for a cuttingmat and sort of ruler???

[Klasien]

On my trip to the USA I'm planning to get a larger cutting mat.
I also want to buy a sort of mat I've seen at a video of Eleonor Burns, she used a mat that she put on top of her fabric that was on her cuttingmat.
Then she could cut between lines and that gave her perfect strips and squares.
I would love to have one of those, but I don't know what they are called and I have no idea what the price is......

Could anybody of you tell me where to go and look for one, the name and the price???
Or does any of you have one and knows if it is any good???

It looked so easy and fun to use, I think it would work also great to cut all the fabric for the Jackobs Ladder Swap, my first project after I get home!!

I hope you guys can help me out here

Thanks!!!