This is my smell detector prototype. First of all, the air goes in from the blue circle (first picture), and inside machine analyzes the smell, and the results are displayed on the screen (the rectangle above the blue circle). Below the blue circle is a red rectangle. This is a speaker. It will reads the results so that you don’t have to look at the screen every time. You can see that in the first and second pictures, the top of the small detector is different. The first one can be hung on the neck like a necklace, and the second one can be hung on the collar or other places, like a pen. Both kinds of tops can be removed and replaced at any time.