Security Bit Steel, eJiasu Security Screwdriver Tool Game Bit 3.8mm+4.5mm for Nintendo NGC/SFC/N64/SEGA Gameboy Open Tools Kit (2pcs) Made of durable strong hardened steel Measure 5 cm (~1.97 inches) in length These bits allow you to open,repair,and to clean different types of video game cartridges and systems 3.8mm one opens Video Game Cartridges for Original Nintendo (NES), Super Nintendo (SNES), Nintendo 64 (N64), Virtual Boy, Original Game Boy, Game Boy Color, and Sega Game Gear 4.5mm one opens Video Game cartridges for Sega Genesis, Sega Master System, and Sega 32X as well as systems for Super Nintendo, Nintendo 64, Game Cube, Virtual Boy, Nomad, Game Gear, TurboGrafx 16, and TurboDuo.