These radios are full-blown Android devices with a robust antenna and battery life, push-to-talk button, channel selector, loud speaker, and capabilities on multiple radio bands. They are a perfect complement for Zello in industrial applications.
Zello does not sell any of these devices.
We have tested them all and we are confident that they are compatible with our push-to-talk apps. However, you should test any of them in your own environment, including your other apps, before standardizing on them or committing to a large purchase.