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.
The mat is fairly thin and it will 'dip' from my weight (I'm not over-weight) & chair. It can make rolling the chair on the map a bit of an effort. I don't have plush carpet but the mat still moves a little - not as much as my previous one.
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.
This mat is good quality and performs well. This mat is medium thickness (mils) and is a very good value for the price. Thanks to Staples for the ability to compare the mil thickness of different mats and free next day delivery.