Despite the naming issues -- my flat pile carpet does not actually have a lip -- but the mat does and it is vinyl. And the little prongy things go DOWN into the carpet. And it works great. Good value and in all seriousness it does not curl as do some. So good on you Staples.
Sits on the floor where I put it. Lies flat. Doesn't move. Protects the hardwood. It's everything I wanted it to be. If you want a chair mat that will do all the things a reasonable person expects a chair mat to do then this chair mat is an excellent choice.
The size and grips on the bottom are working great. It is already indented where the wheels of the chair are. Not sure if that is normal for chair mats.