Not too big not too small it really does have a nice feel to it and is stiff enough for easy rolling without being hard or brittle. Just what I was looking for.
We used this product for under child tables for childcare - works very well & will be durable for this application. I would agree with other posts that these would not work well (or long) with adults on chairs as they are too thin to withstand that kind of pressure. Then again they are half the price of 'good' ones so you do get what you pay for!
Smaller than I expected have about 1 foot of rolling space front to rear under my executive chair. There is about 3.5 inches on the left and right if the chair is centered. It is plenty adequate since I don't roll around too much just have to be mindful about rolling away from the desk. Quality-wise I don't see any cons. Protects the wood floors from my chair's casters.