66 dart LED prototype working for now

A big +1 (or +10) to the advisory regarding the retroreflectors. They need to be present and they need to work. It's extremely difficult to get a good working reflex reflector off a copycat mould. There are many different grades of retroreflective sheeting that vary widely in their brightness and effective angles, so shop carefully. And 3M's got a new material that is both transluscent and retroreflective. Not sure it's available to consumers yet; I'll check with my 3M guy and see what he has to say.