Ridata Double Layer DVD-R 4X silver matte in 25 pcs cakebox New technology allows material to be either read or recorded on one layer without affecting material on the other layer. Storage Capacity: 8.5GB of storage capacity on a single-sided disc -- No need to flip the disc Largest compatible DVD back-up and data archiving format for computer drives Middle zone length can be decided by application/PC in order to shorten finalize time The industry's first Double-Layer DVD-R (DVD-R DL) discs. The new 4x media nearly doubles the storage capacity on DVD recordable discs from 4.7GB to 8.5GB on a single side while maintaining compatibility with existing DVD video players and DVD-ROM drives.