Bests & Worsts Reviews from Amazon

As others have said, the large versions of this mat come 'rolled up' with shipping tape band holding them in position. to unroll, you must put heavy weight on it and let it gently unwind from the bottom of the roll - AWAY from your face and head! I had a full grown man putting all his weight on it when I cut the band off- and we managed to unroll it safely. There are numerous warnings on the box and on the inside packaging, and it's not a joke. Once unrolled, I discovered the good and the bad of the large size mat. The GOOD was that there is plenty of real estate- enough that I was able to slip a goodly portion under my desk, which accomplished an additional benefit of minimizing the 'flex' that this item has when you step onto it. The carpets have pads beneath, which 'give' and the flex in this mat may cause the outer edges to lift up ('bow'), when you step onto it. After sliding a goodly portion under my desk (note the desk legs 'pin' the mat in position)- the flexing issue seemed abated and at first I was satisfied - see edit below. Initially I bought the very smallest version of this 'basic' mat offered by Amazon, worked just fine, but I discovered in most uses I rolled off the edge of the mat which worried me that I might ultimately damage my carpeting. Thus I returned the small version and paid about $60 for the big daddy shown in the photos. Still reasonable, and stands up to my 280-lbs with no issue on 1/2" carpet and pad ("Happy Meal" carpeting) with plywood subfloor. The item laid fairly flat after unrolling- though I did place some heavy objects along the edges to ensure there were no 'trip hazards'. I recommend this mat (the larger size) with the caveat that you may need to put a substantial bit of it under your desk for stability. The 'shine' you see in the photo is caused by my flash camera. I am happy with its transparency and the grippers on the bottom seemed to be holding it in position no issues. However over time, the mat does creep about and moves out of position. EDIT: After exactly 60 days, this mat has cracked in several places and thus I can not recommend it. In fact, I would urge you to avoid purchasing this item as it is not even MINIMALLY durable. I am very disappointed by this failure and of course I can not return it for refund after 30 days.