This infrared thermometer is perfect for measuring the temperature of various hot, hazardous or hard-to-reach objects. Surface temperatures can be taken safely and quickly without contact with the object. Suitable for temperatures from -50 up to 550 degrees Celsius . Operating the unit: Open the battery door and insert a 9V battery. Pull the trigger to turn on the unit. Aim at the target surface and pull the trigger, the temperature will be shown on the LCD. This unit is equipped with a laser, which is used for aiming. To find a hot spot, aim the thermometer outside of interest, then scan across with an up and down motion until you locate the hot spot.