Master Bond MasterSil 151Med is a two component low viscosity silicone compound for high performance casting, potting and encapsulation. The base low viscosity resin after the addition of a liquid curing agent cures at ambient or more quickly at elevated temperatures to a tough, flexible, optically clear silicone rubber. The low viscosity of this silicone elastomer compound assures complete fill-in around complicated contours in even very complex configurations and provides excellent electrical insulation as well as superior resistance to vibration and shock after cure. It has been widely accepted for potting and encapsulation of electronic components, electrical devices and various optical systems as well as a coating for solar cell and fiber optic or wherever a tough, elastic and optically transparent protection against adverse environmental conditions is required. Master Bond also offers a thermally conductive, electrically insulating version called Master Sil 151AO. It has a thermal conductivity of 27 x 10 -4 cal/cm² - sec and has a gray color.