@epierre ，can you please send your email again, it maybe spammed by my server .

Positive answer , we can provide samples . see available types in attachment .Which one do you preferred ?Choose the output interface and I can send communication protocol in advacne .
Just need your information to send products ,your company ,shipping address , contact name , contact phone number .Air Quality Sensor Module Product List (Wuhan Cubic-V2015.1).pdf
Regards
Roy Lee
ruyi.li@gassensor.com.cn

@epierre I am sales manager of CO2 sensor in this company , We didn't retail CO2 sensor . Because the product is designed to built-in IAQ device , we used to cooperate with factory who need sensor on their device .

This products have MOQ reqirement .You can also send more information about your project to my email ruyi.li@gassensor.com.cn
I will see what support we can provide to you .

The sensor price has dropped a lot during the past years , monitor CO2 in house at 0~10000 ppm is becoming popular to remind necessary ventilation .
Using CO2 sensor module for a DIY CO2 monitor is a good choice , of course , this is a OEM products , mostly for using by factory .
See detailed at
http://www.gassensor.com.cn/product_en/typeid/9.html