I bought this item to replace a new one without the "spikes" to hold it in place. When put under the legs of the desk the previous one would warp all over its surface. So I bought the Staples chair mat that I could see at the store. It felt sturdy enough & I thought the spikes would keep it from shifting positions. It didn't. So my father put a desk leg on it to keep it in place. That caused it to warp and it still wouldn't stay in place. It folded up and scraped my Dad's leg. He is on blood thinners so that mad a mess. I have gotten a bound rug remnant to serve as a chair mat so hopefully that will do the job.
I purchased the chair mat to replace the last one I purchased at Staples. The previous one worked great. It was thicker had more holding power and allowed my chair to glide easily across it. This "Pile Carpet Chair Mat was so flimsy that the casters on my office chair made deep grooves in it and would not roll on the mat. It might work fine on hardwood floors or concrete but is worthless on carpet.