DC 4-28V 5V 12V 0.28 inch 0.28 " LED Display Dual Red Blue Green Digital Temperature Sensor Thermometer With NTC Probe Cable Description: Size: 45MM * 26MM Refresh rate: about 1S / times Supply voltage: DC 4-28V Accuracy: 1C Measuring temperature: -20C~ 100C Working temperature: -40Cto 80C Display color: Red + Blue Sensor Type: 1M NTC waterproof metal probe Display: 0.28 LED Minimum resolution: 0.1C Instructions for use: [1] DC power supply: This product requires acce 4-28V DC power supply, the red line for positive power supply, the black wire to the negative power. The greatest feature of this product: its own reverse anti-burning circuit, avoiding the user proce due to improper operation problems. Friendly reminder: must not be connected with AC 220V Oh! [2] Display Description: When the temperature sensor is removed when the digital display "- - -", the temperature is below -20Cor above 100C, digital also shows "- - -." [3] Acquisition normal temperature range: -20Cto 100C, resolution 0.1C, accuracy of 1C. Product Usage: (1) measuring the temperature inside and outside the car (2) measuring the temperature inside and outside the air-conditioned room (3) measuring the temperature inside and outside the refrigerator (4) temperature measurement pond (5) baby bath water temperature measurement Package List : 1 x 0.56 inch digital thermometer 2 x NTC metal waterproof temperature sensor 1 x cable