This Carpet Chair Mat has been under our desk chair for a year. The mat moves around on my 1987 medium pile carpet. However it provides carpet protection & allows chair to move around without the mat being depressed--which is good.
The clear chair mat does the job for my vinyl floor appears to be well made and doesn't slip. Fits well with my desk. Delivered promptly and wasn't curled so I didn't need to flatten it. So far so good.
I see where other customers experienced poor chair rolling cracked mats or moving mats (prongs not long enough to keep mat in place). I purchased two of these mats for two different office chairs/desks. For me the mats are working well. They are staying in place and my chairs are moving quite freely--to the point where I must keep them from rolling from under me (lol). I'll give it some time to see if I experience any cracking but so far no cracks.