The CJMCU-8118 is a gas sensor system-on-chip (SSoC) + temperature and humidity sensor that uses low-power sensing technology to detect indoor volatile organic compounds (VOCs). From the schematic diagram of the CCS811 onboard the CJMCU8118, see that this is not a simple sensor. It also integrates an MCU inside, so that this sensor has on-board processing capabilities, which can provide etc. Effective carbon dioxide level or total volatile organic compound (TVOC) indicator. At the same time, compared to solutions using discrete gas sensors and MCUs, the CCS811 can save equipment bill-of-material costs and up to 60% of the board area. HDC1080 Low-Power, High-Accuracy Digital Humidity Sensor with Temperature Sensor The DC1080 is a digital humidity sensor with an integrated temperature sensor that provides excellent measurement accuracy with ultra-low power consumption. The HDC1080 supports a wide operating supply voltage range and offers low cost and low power consumption for a variety of common applications compared to competing solutions. Humidity and temperature sensors are factory calibrated. Relative Humidity Accuracy 2% (typ) Temperature accuracy is 0.2 C (typ) Excellent stability in high humidity 14-bit measurement resolution 100nA current in sleep mode Module size: 15mm x 21mm Color: As Shown Material: ABS Package Contents: 1 * Carbon Dioxide Sensor Module 1 * Pin 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.