For some reason all around the edge of the mat there was a raised edge that made it a tripping hazard ... as well making it hard to flatten the mat out for use. Ended up returning the mat.
I bought this mat to replace my last one which was also bought at Staples. I believe it's identical to that one My old one started to dry up and crack. I had the old one for over 8 years before the cracks started to appear. Considering I use my desk almost every day for over 8 hours and I'm no lightweight I feel I got great use out of it. As soon as my brother visits I'll put it down and try it out. Any problems with it I'll post an update.
Excellent very sturdy mat with beveled edges. I am 175 pounds and my chair rolls smoothly on it with absolutely NO dimpling or creating "craters" if you sit in one place for a long time. I love the Staples brand design of the prongs; they hold the mat firmly into the carpet without cutting your fingers up when you have to move the mat. Lay it out in the sun on your driveway for about 10 minutes before you bring it inside & it will just "melt" flat for you. Would definitely buy again!!!