The large area of this mat provides complete protection of the carpeting around the seating area of my desk. This is the second one I have purchased. The first performed well for 15 years before cracking in the most used area.
Over all chair will roll over mat better then on carpet. My big issue is when it was shipped they rolled it up and used clear packing tape. It took 3 days to get the mat to lay flat and I'm still after 4 months trying to get tape residue off.
Would not purchase this chair mat again as too soft of plastic allowing mat to indent and making maneuvering difficult. This mat is on residential carpet. My weight is 150 lbs. The new desk chair purchased from Staples as well is a ***** chair having four legs with wheels.