Backlit LCD: The newly upgraded 2.24-inch LCD screen is different from most other products on the market. It has a backlight function. The clear LCD display and power indicator light allow you to see the status of the controller even in a completely dark environment.Heating mode, when the set start temperature is lower than the stop temperature for heating mode, the corresponding icon is displayedReal-time temperature range: -40~120C2.1 Open circuit (or below -45C) The first line of the screen flashes "E1", -40~-45C displays -40C. 2.2 Short circuit (or above 120C) The first row of the screen flashes "E2", 121-129C displays 120C.Safe to use: Plug and play design, using high conductive copper plate, anti-copper rust. Safety socket to prevent children from misplugging. The appearance is made of PC flame retardant material, high temperature resistant and flame retardant. Set the temperature range, place the probe, and plug the heater/cooler into the marked socket. Supports heating and cooling modes, suitable for beginners and professional users.Wide Application: This temperature control socket plug is widely used in greenhouses, reptiles, incubators, glass containers, freezers, refrigerators, heaters, home brewing, breeding boxes, fermentation, heating pads and other temperature control systems. It can also be used as a timer for cycle timing and countdown.