Seven-in-one модуль датчика качества воздуха лазер pm2.5PM10 формальдегид TVOC температура и

Model 1: Standard version (110dB)   Model 2: Adjustable tone version (110dB)   Model 3: Single USB port version (95dB)   Model 4: B version (110dB)     Model B has a different appearance from the standard model. Model B has a larger round head and model B uses a single USB head to work   The standard model uses two USB ports, one USB port is the power supply port, and the other USB port is the control port;   The adjustable version is a standard version with a volume knob on the back (need to be turned with a small flat screwdriver to adjust the volume of the siren);   The sound and brightness of the single USB port are lower than the standard one. The power supply and control use the same USB port, and the volume is about 95dB.       USB sound and light siren Standard volume 110 decibels Computer directly controls the alarm HID free drive, supports secondary development of Windows