All three of the designs agree on the same necessities: the new iPod nano can and should be fully covered on its top, sides, back, and the metal parts of its face. It needs to be open to headphone and Dock Connector plugs on its bottom, and provide some sort of access to the nano?s Hold switch down there, as well. The screen and Click Wheel also need to be easy to use. Whether you pick SportGrip or the others, you?ll find all of those?