Electrically conductive PVC smooth top surface is combined with a dense closed cell PVC foam base UniFusion™ bond guaranteed for the life of the mat Redstop™ non-slip backing to reduce mat slippage Beveled edges on all 4 sides Certified by the NFSI (National Floor Safety Institute) RG 104 to 106 Ω; RP 104 to 106 Ω Grounding cord included, required