Features: PCB onboard installation; 30 to 120 dBA wide range, 20 to 12.5 kHz wide frequency measurement. With this module, customers no longer have to worry about complex noise signal processing, and can focus on areas of expertise and create value for customers faster. Mainly used for various noises such as environmental noise, traffic noise, workplace noise, building construction noise, and social life noise. Pre-polarized back-electrode electret condenser microphone with wide dynamic range and stable performance. Both slow and fast measurement modes are available to meet different requirements. Specifications: Type: TTL 5V / RS485 5V (optional) Note: Please allow 1 to 3 cm error due to manual measurement. Please make sure you do not mind before purchasing. Due to differences between monitors, the picture may not reflect the actual color of the item. Package includes: 1 x Noise Decibel Detection Module