Beware of poor fitment though. I got some cheap wired ones years ago (from Amazon), didn't work so well because they had bad contact and no mechanism for adjustment. Kinda also needed a preamp, though if contact were perfect maybe that'd matter less.

I also am not so sure I'd trust them to be waterproof, and anything that is would likely have a heftier pricetag. That, and I'm pretty tired of everything having batteries.