Double-layer DVD+R recordable disc, the wavelength of the red laser is 650nm, numerical aperture is 0.65, total capacity is 8.5GB. The double layer structure on one side of once written DVD, each layer can be recorded data. 1X velocity is 3.84m/s, the highest supported speed is 8X. Recorder supporting double disc can make the laser head focus on different layers, and then on different layer dye is burned to pit and land of light and shade for saving all data. The tracking direction of the disc on the layer 0 is from the inside out. On the layer 1 the tracking direction of the disc is classified to two kinds: OTP and PTP. Its manufacturing technique: two pieces of substrate with the groove is bonded together. The groove of each substrate need to coat dye and sputter reflective layer. The frequency and the location of the groove are the same as the 4.7GB DVD+R.