I have a few. They are super nice quality. Mine range about 30ish feet. They do not comfortably fit under a helmet though. The top part is a stiff rubber that doesnt really bend to the shape of your head so your helmet wont fit great unless its really big.
I'm going to go with the tags probably. Because I wear my helmet without earpads. Although, I have a really good idea for you guys!!! You should make like a balaclava/yowie thingie that has like pockets on the sides for the chips to slide into! That way you wouldn't need an audio helmet