First of all the mat was not delivered when it was supposed to be and it finally took a phone call to have it re-shipped. Usually chair mats are delivered in a flat box...this mat was delivered folded-up so it did not lay flat. Right now we have some heavy boxes on it trying to flatten it out. Seems to be the correct mat though.
I purchased the chair mat for two reasons: To protect the wood flooring under the desk chair but additionally to muffle some of the sounds of the movement of the chair against the floor (an apartment building). I would have preferred something with a carpet-type of covering but they only seem to be available with little "nubs" underneath to hold them onto a carpeted floor. The "Lip" is an extra extension of the mat that fits slightly under the area of the desk where your feet go. I find that this helps to position the mat and keep it in place. Live Chat was very helpful in guiding me through Staples' inventory to make this selection.
The Chair Mat does not do as advertised ... the grips do not grip so the mat moves when the desk chair rolls - requires constant adjustment back to center location.
Couldn't believe how fast I got it shipped to me- Had to be ordered. Really makes the chair I bought at Staples roll better and feel better. Very helpful employee of Staples. Made it a very pleasant shopping experience and helped me choose one that could be ordered.