I originally had an interactive one, but switched after a conversation with some EMTs who indicated that the more info they had immediately in a critical situation, the better for your treatment. They also advised choosing one of the brighter colors to draw their attention to it (of course I had a black one and one guy said he thought it was my watch at first glance) and not the version that attaches to your shoelaces as direct hits sometimes knock the victim out of their shoes.