A 3480 tape cartridge contains a small reel of half-inch chromium dioxide tape that is enclosed in a compact cartridge for greater tape protection and automatic tape threading. Each tape cartridge records tracks of data in one direction at an approximate density of 38,000 bits per inch, and each tape cartridge can store up to 200 MB of unformatted capacity. A 3480 tape cartridge can transfer data at a rate of 3 MB/sec. 3480 tape cartridges are usually used on mainframes and AS/400s.