Sony's PDP series Pro DAT employ professional grade metal digital tape. A polypropylene case protects the cassette and the high quality DAT sound inside. The PDP series employs ultrafine "Crystal Art" magnetic particles, which deliver high retentivity and outstanding output. HD&R Binder System (High Dispersion & Reliability) enables high-density packing while maintaining flexibility and durability. Together with the specially developed backcoating, it also helps to keep error rate low even after multiple plays.