The title of this article is official, but it comes from a non-English source. If an official name from an English source is found, the article should be moved to its appropriate title.
The Blue Switch is a Japan-exclusive e-Reader card for use with Super Mario Advance 4: Super Mario Bros. 3. It was released in Series 1 in Japan.
Once it is scanned, all of the 1-Up Mushrooms in the game become 3-Up Moons. This feature allows Mario and Luigi to accumulate extra lives more easily.
1UP mushrooms turn into 3up moon!