They are from Shapeways. Look for valve designs on there. A range of Irish kit bits from the Philips rapid prototyping company.
Ive beets too which are excellent!
http://www.shapeways.com/shops/valvedesign
At the moment, 4 units, I'd plan to get a pair of double packs of the non-genny ones when they come out (hopefully!) Am uploading a few vids to youtube atm