Described as 8.5 mil bendable plastic -- they came rolled in a large box. I bought 2 in May so they didn't get cold while in transit - they need to be at room temperature to unroll without risking cracking the plastic. They are intended for hard surfaces (not carpet as it is too thin to stay unwarped over carpet and doesn't have spikes to stay in place) - - both sides are textured a bit to stay in place and provide a bit of resistance to wheeled chairs. The texture surface seem to hold the mat in place while rolling your chair. It's 3 feet wide and 4 feet long and intended for a closed in area -- if you roll your chair a distance from the sitting position you will need a larger mat.
There are two big labels on the chair mat! Be prepared to spend 1 hour of your time with a hair dryer and a bottle of Goo Gone. What were they thinking when the labels were applied. Definitely would not recommend.
Good product...mistake made ordered to replace in all the offices. Be prepared to spend 30 to 60 minutes on each to remove two big label. You will need a hair dryer and Goo Gone. Extremely bad thinking whoever decided to label the mats. DON'T RECOMMEND THE PRODUCT.
I bought this product so my rolling chair would not grab at the carpet. Unfortunately I did not read the full 'recommendation' for the product as I have thick carpet with padding. This mat does not grip the thick carpet and I am constantly having to reposition it because it slides. It might work on the carpet without padding and is listed in the description (which I read after purchasing).