Fellow is the brand behind the entire selection on this page. The available reference from Fellow only lists the product name Pirch Espresso Glasses, so we are sticking to what is actually shown in the range here: electric kettles with clearly different uses.
The key choice is how you want to pour and how much control you want. The Stagg range is designed for manual brewing with a gooseneck spout and is ideal if you want to control the flow precisely. The Corvo range is more versatile for coffee, tea, and other hot drinks, focusing on temperature rather than pouring technique. Clyde is the simplest choice in the range: larger capacity, quick everyday use, and no temperature control. Both Stagg and Corvo include standard models and Pro versions, with Pro offering more features for those who want to fine-tune their routine further.