The LCI-777 is super easy to use. In fact, it very well might have the easiest blow technique when compared to all other competition. It only requires a steady blow into it, no humming or sucking air back in to complete a test. It even has an application for your phone (iOS & Android) that allows you to pre warm it up, making it incredibly convenient as well.
Checkout the video and user manuals below for more information.
