These are really bad mats. 
1. When it is shipped to you, it comes as a roll… it’s been forever and a few rainstorms later - there are still curves in the mat…. It just won’t get flat.
2. The quality is really bad - but I guess I shouldn’t complain about that since the mat is only $8.
3. This is the worst. After every rain.. it just traps tons of water in the mat. If you step on it, your whole shoe is wet - why would they make this an outdoor mat