I have seen a few mentions of these  items on the MS site. But could not find an in depth discussion. After looking at the respective company websites the products appear to be pretty solid (but that’s why the marketing guys put it on the websites).  Is there much experience with the aithre O2 monitor with or without also using the CO monitor (either the installed “edot” or the portable)?  https://aithreaviation.com/collections/all Same question on the P2 audio advisory. With the