This part is a kind of semiconductor called CH402.

Function of this product has COOLING CONTROLLER.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

www.DataSheet.co.kr CH402 COOLING CONTROLLER SPECIFICATIONS SENSOR Sensor type Temperature range (0C) Resolution (0C) PTC probe SUPPLY 36x72 -50 to + 99 85 to 270 VAC/ DC 1 VOLTAGE DISPLAY (AC@ 50 or 60 Hz, 2.75 VA) Optional 24 VAC/ DC 2 digits : 0.5", Bright Red LED's. ON/ OFF with programmable hysteresis Main, High Alarm, Low Alarm ± 0.25% (full scale) Via keys on front panel Heat mode Cool mode PP indicated on display, relay off for probe Open / Over-range / Under range High Alarm: display alternates between ‘HA’ / ‘PV’ value for 1sec Low Alarm: display alternates between ‘LA’ / ‘PV’ value for 1sec FEATURES ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Compact Size Indication in oC & oF selectable High indication accuracy: ± 0.25% PTC sensor (for high accuracy) provide [ ... ]

CH402 PDF Datasheet Download