If they ask, declare it as a medical device.
They're allowed to visually inspect it and ask you to touch it so they can perform an ETD. Anything more and ask for a SUPERVISOR (3 strip) not a lead.
They don't get to play doctor. The best was the id10t at DCA who told me "I know it's a cell phone" to which I replied "I'm pretty sure I know what the medical device I'm wearing is".
Lots of the front line staff are ignorant of their own rules. I've taken to hunting up and telling 3 stripers when their teams need retraining... and it works. SEA has gotten a lot better. Even gotten a thank you once.