**6. Conclusions**

Perceptions and design paradigms about the development of erosion resistant silicone rubber insulators for outdoor insulation using inorganic fillers have been discussed and lessons learned are summarized. The concept of tracking resistance must be recognized as distinct from erosion resistance for silicone rubber. Two aspects must be taken into account when designing erosion resistant silicone rubber insulation housing composites, namely the volume effect of the fillers and the shield effect. In addition the methods of testing the design must be well considered. Supplementary material characterization tests and measurements such as TGA, SEM, leakage current measurements and thermal conductivity measurements are useful in understanding the protective filler actions in enhancing the erosion resistance of silicone rubber.

**Author Contributions:** Conceptualization, R.A.G., Y.H. and H.P; writing—original draft preparation, R.A.G.; writing—review and editing, R.A.G., H.P., and Y.H.; visualization, R.A.G.; supervision, H.P.; project administration, R.A.G.; All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
