Very nice heavy duty there are spikes but they are not sharp. Arrived rolled. I unrolled placed heavy objects on it overnight it was flat and usable the next morning.
The mat looks and works fine But it is a bit softer than I expected. I only weight 155 lbs and when I sit in my little desk chair on the mat the wheels of the chair indent the mat. That seems like a precursor to having the mat crack at some point in the future. But for now it is working fine.