Ketotek’s KT3100 Digital Thermostat Socket is a plug‑in temperature controller with an external NTC 10K probe. It switches connected devices between heating and cooling based on user‑defined start/stop setpoints and offers four timer programs (cycle, countdown on, countdown off, combined), plus a dedicated temperature control mode. The display shows measured, start and stop values, and the unit supports Celsius/Fahrenheit selection, calibration and memory retention after power loss. Typical applications include greenhouses, incubators, reptile habitats, fridges/freezers and space heaters or fans. Operating range is −40 to 120 °C (−40 to 248 °F). Regional variants include 120 V/15 A (US) and 230 V/16 A (EU) versions; both use the same KT3100 platform and wired probe.