How does one use Action Replay for Game Boy Advance?

The Action Replay Max by Datel is an accessory that connects to the Game Boy Advance. Codes are entered into or downloaded to the device to enable cheats and enhancements in certain games.

The Action Replay Max comes pre-programmed with hundreds of codes. Additional codes can be downloaded directly to the device or entered manually. Before starting the game, the Action Replay Max allows the player to activate the codes she wants to use from a list. The codes enable a wide range of cheats in different games, including making the player invincible and giving the player unlimited money. Some codes unlock special features and characters in the game.