Functionality has been confirmed. *The B button feels a bit off, but it responds. The software used for the functionality check is not included. A dedicated screwdriver etc. will be included! This is a beautiful item, used only a few times. [Specifications] - Game Boy / Game Boy Color compatible - Latest firmware Ver 1.1 - IPS LCD screen - USB-C charging (1800mAh battery) - Screen brightness adjustment - High-volume speaker - Clock speed change (up to 1.25x speed) - Communication with Game Boy / Game Boy Color via communication cable Press the volume control button on the left side to open the menu for brightness adjustment, etc.