How to ship a 6-inch neodymium magnet

Neodymium magnets can be so powerful as to be dangerous: you don't want two of them "spotting" one another when a fleshy fingertip is in the way of true love. So how do you ship a 6" one safely?

"So, is it really shielded?" asks YouTube's Braniac, chuckling to himself. "No."

The magnets featured in the video appear to be from—what's a good place to buy irresponsible magnets in the U.S.?