India’s electric network operates under very harsh environments. Industrial Pollution, Marshy Land, Hilly and Un-friendly terrain, Extreme weather, Coastal Region etc. These environmental conditions make insulator contamination flashovers the main concern to the electric utility. Different solutions were tried to combat the insulator pollution flashover. At the beginning there were only Ceramic Insulators. Later Glass Insulators were put to use, but not found very useful. Introduction of Composite (Polymer) Insulators OR Silicone Insulators in 1970s was a turning point. Silicone rubber insulators are generally acknowledged by their superior pollution performance. They are found to be useful in sever weather conditions, They have distinctively hydrophobic surface, they are good resistant to Chemical Influence, Weathering, UV Radiation, their Physiochemical and Mechanical Properties remain constant over wide temperature range. Results showed negligible changes in Polymer Insulator properties and no electrical or mechanical failures were experienced in long run. It is found that "composite insulators" can be specified, manufactured, tested and maintained to be reliable for their service life for HVAC and HVDC applications and hence they are now used in most HV applications.