If you want to use your NDS in a way that gets the full use of this amazing and entertaining device, then you will need to get a R4 DSi storage card. While there are many places you could potentially purchase this card it is important to look around and find the best price possible for the card. These particular cards are being sold all over the place. If you want to search the Internet you are bound to find several site that offer them. there are also many retailers that sell them as well. Once you have found the best and most fair price, it is time to buy.