The product is ok but all the floor mats seem to be the same standard size... I could use a larger one and putting two together just jams up the rollers on the chair when I try to move over the gap. Maybe because it's on carpet but then again if it were just another three feet longer it would be no problem.
As it is thin chair wheels sink in at take a "set " which can make it initially hard to roll the chair. I suspect this will lead to it breaking down (they all do) faster needing earlier replacement. It is a nice size. The thicker (and more expensive) ones were much bigger.
I use this mat over a vinyl floor. It needs to be much thicker to provide a smooth rolling surface. I have a chair with 5 casters on it and they create divots on the mat. I weigh 200 pounds; so that distibuted over 5 casters should not create divots in a supposedly solid pad.