Dual-layer recording allows DVD-R and DVD+R discs to store significantly more data, up to 8.5 gigabytes per side, per disc, compared with 4.7 gigabytes for single-layer discs. This allows for 2 full hours of digital video at XP quality. We recommend these discs for transfer of S-VHS, Hi8 and Digital8 video that are longer than 1 hour.