Before you buy, you must be in an area that has the Sprint network.
Then you need to purchase the Internet On The Go Mobile Hotspot device, http://www.walmart.com/ip/Internet-on-the-Go-Mobile-Hotspot-3G/20665535
Then you buy these prepaid cards.
Once you have it setup you can use your wireless devices with it, IPad, Iphone, laptops, tablets, ereaders, Nook, Kindle, printer, etc etc etc.
You need an Internet To Go hotspot (sold here at Walmart.com). This card does NOT work with any other hotspot or service.