Dual-layer discs also employ a second recorded layer, however both are readable from the same side (and unreadable from the other). These DVD-9 discs (Type C in ISO) nearly double the capacity of DVD-5 discs to a nominal 8.5 GB, but fall below the overall capacity of DVD-10 discs due to differences in the physical data structure of the additional recorded layer. However, the advantage of not needing to flip the disc to access the complete recorded data – permitting a nearly contiguous experience for A/V content whose size exceeds the capacity of a single layer – proved a more favorable option for mass-produced DVD movies.