Features:Working voltage:DC4-30V.Temperature range:-50 C ~ 120 C.2 types for your option: annular sensor/rod sensor.Easy installation: Red wire for positive, black wire for negative.Widely used in the fish for tank, refrigerator, water, temperature control for protection, etc . Specifications:Material: ABS Type: annular sensor/rod sensor(optional)Operating voltage: DC4-30VTemperature measurement: -50~120 error 1.7 (not adjustable)Working current: equal or less than 20mATemperature sensor: ring-shaped or rod-shaped 3950 10k1% sensor, length 100cm Note:Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes:1x Digital Thermometer