Here is how to use a three piece airlock for homebrewing.
You can get your own airlock here: https://www.homebrewohio.com/search.php?search_query=three%20piece&utm_source=yt&utm_medium=yt&utm_campaign=yt
You can get your own airlock here: https://www.homebrewohio.com/search.php?search_query=three%20piece&utm_source=yt&utm_medium=yt&utm_campaign=yt