Phase-change Dual (or Phase-change Disc) is a rewritable optical disc and a standard for it, developed by Matsushita Electric Industrial Co. , Ltd. in April 1995. It has a capacity of 650 MB on one side, and the size of the disc is 12 cm in diameter (5 inches) similar to a general CD or DVD, and it is used in a state where it is housed in a square cartridge. The phase change recording technology using red laser light is adopted, and about 500,000 times of rewriting is possible.