There are many r4 cards on the market that are known under various aliases such as r4 cards, r4 revolution, r4 adaptors, r4 adapters, ds cards or sometimes just r4. The r4 card most suitable for use with different consoles varies. The r4 card is a slot 1 device meaning that all r4 cards slot into the space commonly used for a original ds cartridge. This means, that although each r4 card looks similar they vary in compatibility with differing console types. R4 cards are also known as a r4 adaptor or r4 adapter as the r4 card itself only facilitates the communication (hence its name) between the micro sd memory card and the console for operation. Such usage will open up the consoles multimedia capacity so that it can be used for reading ebooks, listening to music, watch videos and also for playing home brew games.