Accurate & Instant Reading Non-Contact Forehead Thermometer with 3 in 1 Digital LCD Display for Take a Human Body Temperature in Just Rs 1999 with 10 days Money Back Guarantee for Customer Satisfaction Accurate measurement: The product adopts the optical principle, the measurement accuracy is controlled at ± 0.2 ℃. Simple operation: The product supports one-button temperature measurement. Convenient reading: The product adopts digital display reading mode and supports back light design. High safety performance: The product supports non-contact measurement, which greatly improves safety. Correction settings: F1-Unit setting-F1 Function (factory default is degree Celsius) F2-Hint Sound Switch Setup (factory default hint sound on) F3-High fever warning setting-F3 (factory is ℃ 37.5) F4-Back light setting ( factory default on) F5-Exit Setup Mod When in F1/F2/F3/F4 state, long-press the setting key(setup) for 3 seconds to automatically exit the setting.