E-Reader (Gameboy Advance)

The e-Reader (カードeリーダー Kādo-Ī-Rīdā, Card-e-Reader) is a add-on made by Nintendo for its Game Boy Advance portable video game system. It was released in Japan in December 2001, with a North American release following in September 2002. It has an LED scanner that reads "e-Reader cards", paper cards with specially encoded data printed on them.

Depending on the card and associated game, the e-cards are typically used in a key-like function to unlock secret items, levels, or play mini-games when swiped through the reader. The cards themselves contain data, as opposed to unlocking data already on the device itself.