This is the first item I have ordered from Wayfair that I am no completely satisfied with.  The mat arrives rolled up, in a box.  (I was aware of this when I ordered it.) What I was no ready for was the struggle to flatten the mat.  Before using it I had it on a flat surface with heavy objects on it.  When I could no longer wait to use it I moved it to my office where it is only flat in the area where my chair rolls. Under my feet it has little "hills." I'm not walking across it so there is no chance I will trip on it.  Honestly, I saw other reviews which said it did not lay flat, but there were those that were very positive.  I will not purchase another chair mat like this. There are plenty of other chair mats at Wayfair to choose from.