ZS-Solid Core Post Insulators;ZSX-Catanary Post Insulators;C-Operation Post Insulators;W-Anti-pollution Type; Numerator after frist"-"-Rated Voltage;Denominator-Catilever Failing Load;N-Torsion Failing Load;L- Lisebelisoa tse ka tlase le tse ka Holimo kaofela li na le Screw Hole;Data kamora motsotsoana"-"-Class of Pollution Level.