The purpose of this cartridge is to cheat in Konami games. With supported Konami titles you can typically change the starting level and number of lives. In addition you can also take screenshots and keep high score rankings.
There is a minor difference in the Japanese and European ROM version. The Game Master text on the title screen is shown in Japanese on the Japanese version.
The Japanese titles means Cartridge to Enjoy Konami's Game 10 Times More.