Then again they aren’t TSO certified, so technically not approved per the Spirit FOM. So there is that.

The TSO process isn’t cheap, and thus why CA and Bose are much more expensive. I use Bose PF2 and love them, FO is free to lose theirs at 18, mine stay on. I wish I had been as concerned about my hearing when I was younger and I wouldn’t have as much hearing loss as I do now. At this rate I’ll likely need hearing aids before I retire. $1k is nothing to protect your hearing, I’d pay 10x that to get my hearing back to when I was young.