Glass Probe Thermistor The 121-202EAJ-Q01 thermistor is hermetically sealed and highly reliable. This Honeywell Thermistor has weldable, solderable dumet leads and maximum temperature range of 260 °C. Thermistors are temperature sensitive devices. They are built to show large change in resistance to corresponding small change in temperature. Electrical resistance change of these thermal resistors can either be positively or negatively correlated to the temperature change. This Quality Thermistor is primarily used in the fields of military, aerospace and oceanography. 121 Series Thermistors are shock resistant, rugged, glass-encapsulated units that are often suited for immersion in fluid and convenient for mounting in air sensor assemblies. They have wide applications owing to their predictable, precise and stable properties.