Hi,
Yesterday I got the carbon monoxide detector that I had ordered a while ago for roadtesting and I wanted to share the video from the teardown. I did this teardown in order to disable the piezoelectric buzzer, which is very loud, especially when you want to test it while you are in the short range.
The device itself is a simple design. The one thing I am not sure what it is inside, is the metal can. The user manual says that the detector is only for carbon monoxide, but this metal piece can be some smoke detector – I do not know. If you have other ideas or you know by fact what it is, please share it in the comments. I do not want to tamper with this can, because some smoke detectors have some radioactive materials inside – usually this fact is marked with a skull or a hazard sign. The level of the radiation should be low, but I would not dare to carry it in my pocket on everyday basis 
Below, you can check the video. In couple of days I will share with you some information about power consumption of this specific detector. I will get this data with a help of the EFM32 STK board. Till next time.