DDS4 delivers 40GB (compressed) storage in a tiny standard tape Cartridge. This 4mm DDS tape cartridge is 120 meters long and stores 4GB of uncompressed data and 8GB of compressed data. Sony's DDS (Digital Data Storage) cartridges last up to 1, 000 write/rewrite cycles, feature a heat resistant shell that withstands high temperature, a anti-static shell that attracts less dust and helps maintain low error rates, and internal components that are designed to reduce torque and provide better drive compatibility. They come in tough polypropylene storage cases.