These are standard size cards with little chips in them so you can bring the characters to life in either Happy Home Designer or New Leaf(after the update early November 2016)

These cards are a lot of fun to use in the Animal Crossing games New Leaf and Happy Home Designer

You can use these cards to get people to move into your town in New Leaf, or you can use them to recruit the character as a client in Happy Home Designer, and design their home

Works great with Animal Crossing New Leaf and Happy Home Designer.

I own both New Leaf and Happy Home Designer, which these work with (as long as you have Amiibo capabilities in your 2DS or 3DS)