Sony LTO 6 Ultrium Tape Library Pack of 20 (20LTX2500GL)

Sonys LTO 6 tape cartridges feature a storage capacity of 2.5TB (native) to 6.25TB (compressed) with higher transfer rates of 160 MB/s(native) to 400MB/s(compressed). The new cartridge is manufactured with fine magnetic particles and a higher thermal stability binder. In order to maximize performance an improved dispersing technology for these particles was introduced

You will need an LTO 6 drive to read your LTO 6 media. However, the drives are "backwards compatible". When you upgrade to an LTO 6 drive, it will still be able to read and write your LTO 5 cartridges, and read your LTO 4 tapes.