On set I see a ton of Comply Foam Tips because they can be thrown into a lot of the generic security earpieces, I don't know the specific size but I can tell you I just pulled three random security earpieces of out my
backpack and a box of
Shure SE
IEM tips and every variety of tip made for the
Shure SE tips worked on all of the random security earpieces I have.
Pandemic aside, I'm a huge fan of just letting everyone own the security earpieces and never ever ever getting them returned to me, I know budgets vary all over but out of all the gear in all the years I've lent out nothing comes back more gross than security earpieces. A few years of managing 300 radio rentals with earpieces and they just get so disgusting so quick, people
throw them in pockets, in backpacks,
etc. If you buy them in a large enough quantity the price gets down to like $6-$7 a
unit and for me the piece of mind to not deal with a box of biohazard spaghetti is well worth it.
Rant aside, if you have any Fist Mic/Biscuits, the
OEM motorola dudes have a 3.5mm output you can run
headphones into it and just use whatever
headphones you like.
+1 for EarHero, while I haven't used them I've been eyeing them for a few years now and at $150 they are spendy but after a year of working in TV where they only use security earpieces I'm now a convert and the EarHero potentially looks unobtrusive enough to slide in during the mix of a show when the A2 is trying to get my attention. They are definitely one of the things I'll be buying myself the next tour gig that comes my way.