thseng...I would use it as an area light, and no need to focus or have a lens.... the one's I was referring to had no switch, you simply snapped the button fastener on or removed it...it was a poured epoxy top, and resistor to reduce the voltage was not visible (if there was one)... they were very well made, and the connector buttons were above average quality...I've never had good luck with the typical 9v snap on strip, as I tend to destroy the strip after about a dozen battery changes...