Duo-Lock Reversible Felt and Rubber Non-Slip Rug Pad, Size: 8' Round Duo-Lock is a needle punched felt surface with a textured rubber lower surface to prevent slipping. Safe on all floors. Non-slip for all rugs and all hard floors. Reversible to keep rugs flat on carpet. Duo-Lock does not mark or stain floors. Contributes to LEED for a greener environment with no chemicals that out gas. Duo-Lock is Made in the USA - .25 inches thick. Mold, mildew and moth resistant.