This mat looks good and doesn't slip. But the weight of the chair and user will cause the plastic to stretch and form a dimple under each wheel after about 10 minutes of sitting still. So trying to roll out of the dimples is annoying. I'm using a 5 wheeled office chair and weigh 160lbs. So far the dimples are not permanent.
This works great and is big enough to move around. We have thick berber carpet and it still works great. They don't last but 2 - 3 years. I wish they could last longer because they are not cheap.