I've built and used many of C. Brent Dane's [link=http://www.cliftech.com/pdf/Optoglo.pdf]OPTOGLO[/link]. It works very well. I still have enough parts to make a couple more but when I have to reorder parts for more, I plan on giving the [link=http://www.cliftech.com/pdf/OptogloII.pdf]OPTOGLO II[/link] a try.