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.