DESCO 66045 Blue Rubber Statfree T2 Dissipative Mat, Dual-Layer, 48 x 24" (Length x Width), 0.06" Thick Dual-layer dissipative mat provides a path-to-ground and eliminates static charge generation when used as a work surface Nitrile rubber compound resists abrasion, stretching, and tearing, soldering flux Non-humidity dependence provides consistent electrical performance regardless of ambient humidity Blue top layer surface resistance (1 x 106 to &lt; 1 x 109 ohms Rtt) meets ANSI/ESD S20.20 work surface required limit Black bottom layer conductivity (&lt;1 x 106 Rtt) reduces the resistance to ground (Rtg) from the top of the surface to the groundable point ground