Zero false alarm rate, Real-time response Correct data Minimum distinguishable particle diameter: 0.3 micrometer High anti-interference performance due to the patented six-sided shielding structure Optional direction of air inlet and outlet to accommodate different designs PIN1: VCC power supply 5V PIN2: GND power ground PIN3: NC PIN4: RXD: Serial port receiving pin (3.3V level) PIN5: TXD: Serial port sending pin (3.3V level) PIN6: RESET: Should remain suspended during use. Lowering may cause module malfunction PIN7: NC PIN8: PWM: Pulse width signal output pin (3.3V level) Circuit design considerations: 1) D9 requires a 5V power supply as the fan needs 5V drive. However, data communication and control pins require 3.3V logic level. Therefore, the main board MCU used for communication should operate at 3.3V. If a 5V MCU is used, a level conversion circuit or chip must be added on the communication lines (RXD, TXD) and control lines (SET, RESET). 2) For serial output, only connect PIN1, PIN2, and PIN5; other pins are not required. 3) For PWM output, only connect PIN1, PIN2, and PIN8; other pins are not required. Color: Silver Material: Metal Package Contents: 1 x Sensor Module Note: Light reflection and differences in display screens may cause slight color variations between the item in the image and the actual product. Measurement error allowance is +/- 1-3 cm. Only the items listed above are included; other products are not included.