This Polycarbonate disc was invented by Pioneer in 1997, and can be recorded at upto 16x (which means a 60minute recording can be done in 5mins). This has fast become the leading optical storage media for video and data. They can only be recorded on once, with a red DVD laser.
These are manufactured by bonding two 0.6mm layers of disc together which make them more stable than CDR media as they only have one layer. One layer has the laser guided grooves while the other is there to secure that the disc is stable.