Product details:

Specifically design for use carpeted surfaces, these heavy-duty chair mats protect floors and allow desk chairs to move around with ease. These chair mats increase range and ease of motion while seated on carpet. See the CHAIR MAT THICKNESS link below for more info. - Custom chair mat shapes and sizes available. The lip protects the floor under the desk where the chair may roll if scooted all the way in. The picture to the left has a lip. - NOTE: Chair Mats with a lip are listed using the overall size of the mat including the lip; thus, the rectangular portion of the mat is smaller than the corresponding size listed.