The R4i is a storage device for the Nintendo DS, DSi and purportedly the 3DS. Players can use the R4i card to download and play games on their DS. The card is in the shape of a DS cartridge and has a port at the top to input a micro SD card which stores game information. Due to the huge success of the R4 and R4i cards, there have been a huge number of clones that feature telltale signs of fraud.
Look at the front of your R4i card for the white circle with the 'i' in it. If your R4i card is authentic, the 'i' will fit in the circle with plenty of white around it. Fake R4i cards have a bold 'i' which practically touches the top and the bottom of the white circle.
Study the circuit board on the back of the R4i card. Authentic R4i's will have 'r4i' printed in white in the top left corner of the board. Also observe the gold strips. They should all be longer than those on a fake card and will practically all reach the bottom of the board.
Look at the box and the cartridge itself. Official R4i cards will have the correct website listed as www.r4i-sdhc.com. If your R4i card has any other web address on it, then it is a fake.
Turn the R4i card around to the back. Authentic R4i cards will feature a holographic sticker which states "Please Access the Official Web Site TRUTH ENQUIRY" which you can peel off to reveal a four-tiered code. Visit the website printed on the front of the R4i card and click the "Forgery-proof search" link in the top right corner of the screen. Enter the number into the box provided for confirmation of authenticity.
Fake R4i cards may be harmful to your DS even if they appear to work fine.