The excellent mechanical and electrical properties of natural mica makes it a most reliable and dependable insulators for use as mounting washers for POWER TRANSISTORS, DIODES, RECTIFIERS, IC's and other Semiconductor Devices. Precision punched natural mica insulators and supports help the semiconductors devices fully insulated from the chassis. They play a dual function. To dissipate the heat away from the semiconductors devices and at the same time keeping them cool. Their added advantages are low moisture absorption, high breakdown voltage and high surface leakage resistance.