The 66L090 is a RoHS-compliant, subminiature bimetallic thermostat in an 8-pin DIP package designed for accurate temperature sensing and switching in a single device. It features gold-plated contacts, positive snap action operation, and can be configured for either close-on-rise or open-on-rise functionality with factory-preset, non-adjustable temperature settings. The device operates over a temperature range of 40°C to 130°C with a standard tolerance of ±5°C, achieving contact ratings up to 1.0 A at 48 VDC or 120 VAC, and low-level switching down to 0.001 A at 5 VDC with up to 100,000 life cycles. Its compact size and sealed epoxy construction make it ideal for space-constrained PC board applications, and it is suitable for use with auto-insertion equipment and wave soldering processes. Typical applications include computers and peripherals, aircraft, automotive systems, and test equipment, where it can control indicator lights, audible alarms, display messages, or system shutdown functions.