The MBC3 chip is not installed on this version. You must source your own and solder it to this cart
You can build your own regular version of HDR's cart by visiting his GitHub page here: https://github.com/HDR/MBC3-Flashcart
Game Boy FRAM RTC Flash Cartridge
Features:
2 Megabyte re-programmable flash for ROM storage
32 Kilobyte non-volatile RAM (FRAM)
MBC3 chip (after installed) with Real Time Clock Function.
Game will still save without the battery. No risk of lost save data.
CR2032 battery clip (no soldering required to change battery)
Compatible with all Gameboy peripherals (Transfer Pak, GameShark, etc.)
Playable on all Gameboy hardware (DMG, GBP, GBC, GBA, Super Gameboy, Gameboy Player, etc.)
Supports RTC and non-RTC titles.
Plays ROM hacks and homebrew titles.