Adopt high-quality double-panel design with power indicator and TTL signal output indicator. With DO switch signal (TTL) output and AO analog signal output. TTL output provides high and low level signals, compatible with microcontrollers or relay modules. Analog output voltage varies with gas concentration, featuring fast response and recovery. Offers long service life and reliable stability. Electrical specifications: Input voltage: DC 5V Power consumption: 150mA DO output: TTL digital signal (0 and 1, corresponding to 0.1V and 5V) AO output: Analog level signal Note: After powering on the sensor, allow approximately 20 seconds for preheating to ensure stable readings. It is normal for the sensor to generate heat during operation due to the internal heating element. Wiring instructions: 1. VCC: Connect to positive terminal of power supply (5V) 2. GND: Connect to negative terminal of power supply 3. DO: TTL switch signal output 4. AO: Analog signal output Material: Metal Color: Green Package includes: 1 x MQ131 High Concentration Ozone Sensor Note: The package includes only the items listed above. Other accessories are not included. Lighting and display settings may cause slight variations in color between the product image and actual item. Measurement error allowance is +/- 1-3 cm.