Switchboard Matting - 

Switchboard matting contains dielectric resistances
of 20,000 to tested 40,000 volts and is an extraordinarily
insulative floor runner material providing the utmost in
electrical shock protection for those working in and around
high voltage electrical equipment.  It is made from high
quality rubber. The corrugated surface acts as
a safety tread while reducing the possibility of metal
particles becoming inbedded.