Maxell rewritable optical disks can be erased and re-recoreded millions of times. All Maxell optical disks are housed in a sturdy polycarbonate plastic cartridge, with a shutter which opens and closes for drive head access. This design protects the disk surface from exposure to dirt and dust that can cause read/write errors. Long disk life has been achieved through the combination of a high-grade polycarbonate substrate, reliable recording and an anti-corrosive protective resin. This 4.1GB 5.25" disk is perfect for storage intensive files like graphics, images, and large databases.