kopack PVC Chair Mat for Hard Floor Protection 36" x 48"1.8MM Thick with Lip (M, Grey L) Updated Version: We adjusted the Chair Mat to improve after Months test.This is a new version design for Cold Winter which performs better to return to be flatter.Tips: If your place is too cold,the best way to flatter is a hot shower to soften it. After you soften it, you can put it flat and roll it as the packed crease with opposite direction,then put it flat,leave the mat for a few hours, and it will become flat without crease. Chair floor mat made of polyvinyl chloride (PVC). Perfect office floor mat for hardwood, tile, laminate, concrete, and vinyl floors. Size:36* 48 inch with lips design.Please note,if the mat may not lay flat,use hot water,the material will get soft to lay flat. Highly transparent chair mat, provide hard floor protection but also allowing the beauty of your floor to shine through.The edge of the mat are polished to smooth, prevent any possible hurt under usage. Heavy duty chair mat, 1.8mm thicker than average mat to protect your hard floor from scratches and marks. Built to last, no cracks, curls, break for long time of usage. Sturdy and firm surface desk chair mat, easy to rolling your chair and not make any depressions even for long time use.