W1209 12V Digital Temperature Controller Thermostat Module

The W1209 12V digital temperature controller is a compact, cost-effective module for automating heating or cooling in DIY projects. A bright 3‑digit LED display shows real‑time temperature while simple controls let you set precise trigger points for reliable, set‑and‑forget operation. The firmware supports HEATING & COOLING MODES so the relay can be configured to switch a heater when cold or a fan when hot, and adjustable hysteresis helps prevent rapid cycling. It ships with a 50 cm waterproof NTC probe and the onboard relay is rated for up to 10 A (120 VAC / 14 VDC), making it suitable for incubators (stable 37.5°C), brewing setups, and basic overheating protection for electronics.