TDK write-once 100% Certified Recordable Compact Discs (CD-R) offer high-density storage and superior audio recording. TDK 100% Certified CD-R discs are high-reliability, high-durability media that incorporate the latest TDK sixth-generation CD-R technologies, including ISOPURE recording dye technology utilizing a re-tuned MSi (metal-stabilized cyanine) recording material for higher sensitivity and improved Reflex Mirror Tuning reflective layer technology.