Bamboo Foldable Dark Cherry 48" x 60" No Lip 5/16" Thickness Chair Mats Felt backing keeps these mats firmly in place on all hard floors and plush carpeting 4/16" thick or less. Heated in a kiln oven to the ideal moisture content to prevent warping and cracking. Comes in 5/16" (8 mm) thickness with 2" wide slats and rolls up for storage. UV-cured coating prevents fading caused by sunlight. Soft polyurethane or soft rubber wheels on chairs advised. Rounded mat corners prevent scratches, trips and falls. A "lip" is the tongue that extends from the mat which covers the floor area under the desk. The dimensions of mats with a lip are listed below in the pricing chart. The dimensions are the total size of the mats including the lip.