Features: The product adopts 4-digit display, which makes the reading data clearer and more convenient. High sensitivity sensor, fast measurement and more accurate. The measuring range is 30-130db, which is suitable for the measurement of sound or noise in most occasions. Suitable for sound quality control in factories, offices, homes, schools and construction sites. With maximum and minimum hold function. Data hold function. Red backlit alarm and audible alarm. Automatic or manual power off function. Temperature measurement function. Specifications: Brand: SMART SENSOR Model: ST9604 Measure range 30-130dBA Accuracy ±1.5db reference SPLpoint at 94dB@1KHz） Frequency Weighting A weighting Frequency range 31.5Hz-8.5KHz Sampling rate 2 times/second Data Hold Maximum and Minimum hold Digital display 4digits Resolution 0.1dB Temperature measurement range -10°C~50℃（14F-122F) Accuracy ±2℃ Resolution 0.1℃ Microphone 1/2inch Electret Condenser Microphone Power supply AAA battery X 3 (Not included) Package List: 1* Sound Level Meter 1*Instruction Manual .