M-DISC 4.7GB DVD+R Permanent Data Archival/Backup Blank Disc Media - 20-Pack Engraves and stores data for over a 1000+ years (M-Disc Ready Drives / Duplicators required) Data stored in an M-Disc is readable with current DVD drives. Composed of chemically stable and heat-resistant materials that are not used in any other DVD or optical disc. Cannot be overwritten, erased or corrupted by natural processes. Passed U.S. Department of Defense rigorous test. DVD+R 4X. 4.7 GB can store up to 8,000 photos, 240 minutes of video, or over 100,000 documents.