Pro am iems?

During the pro am I noticed that a lot of the pros were using iems and then putting headphones over them. Was wondering if anyone knows which iems they were and/or if anyone uses iems for Fortnite? Currently I have like a lot of people hyper X cloud II but cant hep but think that it’s not the best audio. I do own a couple of sets of iems the thruthear red zeros and the Salnotes 7hz zero. But they aren’t the best for Fortnite and I am not an audio geek and dont want to learn how to tune them.