The 66F040 is a subminiature bimetallic thermostat from the Airpax 6600 series designed for accurate temperature sensing and switching in a single device. It features an 8-pin DIP package conforming to international standards, gold-plated contacts, and RoHS compliance per EU directive 2002/95/EC. The thermostat provides positive snap action with either close-on-rise or open-on-rise operation, achieving up to 30,000 life cycles at 120 VAC maximum standard amperage and up to 100,000 life cycles with gold contact amperage at 5 VDC. Operating over a temperature range of 40°C to 130°C with ±5°C tolerance, it delivers contact ratings of 1.0 A at 48 VDC or 120 VAC, and low-level switching down to 0.001 A at 5 VDC. The device is ideal for space-constrained applications on printed circuit boards and is sealed for wave soldering and board washing operations, making it suitable for computers, aircraft, automotive systems, and test equipment where reliable thermal control and switching are required.