Enhanced Sensitivity and Accuracy: The MQ138 sensor module is engineered for precise detection of harmful gases, making it an essential tool for environmental monitoring and industrial safety applications. Easy Integration and Operation: Designed with user convenience in mind, the MQ138 module can be easily integrated into existing systems with minimal setup required, facilitating seamless operation and real-time monitoring. and Reliable: Built to last, the MQ138 sensor module boasts a robust construction that withstands harsh environments and ensures long-term reliability and performance stability. Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Color: As Shown Material: plastic+metal Package Contents: 1 * formaldehyde Sensor Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.