These are pre-flashed action replays with the pseudo Saturn Kai version 6.408 firmware on them. These cartridges are designed to allow you to play backups imports and will also act as a 1M or 4M ram expansion. Please keep in mind you can make these yourself with various different methods. But this will be a easier route for you and this is only offered as a convenience for people who don't want to go through a process of opening their system to flash a cartridge.
Please consider supporting the creator of the pseudo Saturn software by joining his patreon.