This is a gift card that adds USD to your iTunes U.S. account. The balance never expires. You could create iTunes U.S. account WITHOUT any US credit card.
Benefits
Guide on How to Create U.S. Account without U.S. Credit Card
http://support.apple.com/kb/HT2534?viewlocale=en_US&locale=en_US
How to Use
Enter the code from the card to redeem the amount
3 Simple Steps
(We don't deliver physical cards)
Contact:
Mobile: +65-8228 4353