Luigi Power Up!

A Yellow Switch is a Japan-exclusive e-Reader card in Super Mario Advance 4: Super Mario Bros. 3. Released in Series 1 in Japan, it gives Luigi his scuttle ability from Super Mario Bros. 2 and makes his fireballs bounce higher, as in Super Mario World: Super Mario Advance 2. It can be used in the main game, and in World-e (technically, it is permanently on in World-e without ever needing to scan the card).

Japanese
ルイージパワーアップ!

Translation
Luigi Power Up!