If you cannot find Split4G, here are three excellent alternatives:
Split4G is a legacy homebrew tool. While there is no "official" corporate website, it is widely hosted on reputable homebrew and community archives:
reaching 9GB for a single file—users who utilized external hard drives to back up their physical discs faced a wall. The standard operating system simply would not allow these large files to be copied to an external USB drive. How Split4G Solves the Problem