Right after I published the Grassinator build article at Ztrains.com I received a lot of email telling me the source I cited in the article for the negative ion generators (Electronic Goldmine) ran out of these little devices. It appears that they are now back in stock as of May 19, 2008. Link and part numbers are in the article: Ztrains: The Grassinator, Static Grass Applicator Build away! John Cubbin