Want to buy: clam tube (12-16 inches wide)

Hi all, I'm looking for a clam tube 12-16 inches in diam, around 3 feet long. Anyone have one to sell or have any leads? I live in Redwood City, work in South SF.

Thanks!
Bryan

bryan.hains (at) gmail

I bought mine from the Lawson's landing store. Just FYI if you're headed there to get your clam on.