I was getting the occasional click and pop while recording with my Presonus Digimax D8 into a Focusrite 18i6 via ADAT. A bit of internetting later, it seemed that attaching one of these 75 Ohms BNC terminators to the word clock output might fix the issue.
I ordered it, attached it and the problems stopped immediately. This particular item worked so well that I instantly forgot I'd attached it, and only remembered when Thomann prompted me to write a review about it. More than two years later and it's still on my D8, quietly doing its thing and ensuring I get glitch-free recordings.
A simple, cheap fix to a very frustrating (and time-consuming to fix) hardware issue.