HP BD-RDL 50GB 6X Blu-ray double-layer recordable disc offers 50 gigabytes of write-once storage capacity. It records and playbacks high-definition video (HD), as well as storing large amounts of data. A double-layer Blu-ray disc can hold 50GB, which can be used to record over 4 hours of HDTV. Blu-ray uses a blue-violet laser to read and write data. HP, the inventor of the CD/DVD technology also the Blu-ray standards committee member offers high-quality, highly reliable qualified media.