66L065 is a subminiature bimetallic disc thermostat from the Airpax 6600 Series, designed for accurate and reliable temperature sensing and switching in a compact 8-pin DIP package. This single pole/single throw device features open on rise (limit) operation with a factory-preset operating temperature of 65°C (±5°C tolerance), minimum differential of 4°C, and minimum reset temperature of 40°C. The thermostat offers gold-plated contacts with up to 100,000 life cycles at low-level switching (0.001A to 0.020A at 5VDC) and up to 30,000 cycles at 1A/120VAC. It is sealed with high-temperature epoxy to withstand wave soldering and board washing operations, making it ideal for surface and air sensing on printed circuit boards. Common applications include computers, computer peripherals, aircraft, automotive, and test equipment for indicator lights, audible alarms, or system shutdown circuits.