The reactor is attached to an old heart rate monitor strap and it's powered by a 3 volt battery pack that just slips in my jeans pocket. It's light weight and is comfortable to wear for several hours at a time. In the photos below you can see how bright it is- it easily shines through my t-shirt under normal office lighting conditions and is very bright at night.
Follow along and see how it's made.....
Update: see page six for the new style reactor!
Another update! Many people have asked for a kit and a fellow RPF board member has produced a fantastic kit and said I could post a link. This is a very nice kit for anyone wanting to build a wearable arc reactor-