21 ELECTRICAL APPARATUS AND SUPPLIES-NAMELY, HERMETIC SEALS, SINGLE AND MULTIPLE TERMINAL HEADERS, END SEAIS, TRANSISTOR MOUNTS, CRYSTAL HOLDERS, INFRA-RED WINDOW SEALS, HERMETICALLY SEALED THERMOCOUPLE AND HEATER HOUSINGS, QUARTZ CELLS, HIGH VOLTAGE HERMETIC TERMINALS, AND DIELECTRIC STEMS FOR EVACUATED AND GAS FILLED HOUSINGS