Their website does a great job of selling the tech and explaining how you get them the dimensions for your ear (download the app, duh!). They also have a particularly weird commercial that continues to lend itself to my enjoyment of the product - without ever having used them. It's great to see 3D tech actually being applied in a real world scenario instead of just theoretically.
Theoretically, these are awesome. The pricetag is a bit steep for my blood but they are truly one of a kind.*
* unless you have an identical sibling with the exact same ear. then it's just a smart investment.