Back up your important data with this 10-pack of 700MB CD-RW 4x Discs from Sony. Each single-sided disc can be used to record either data or audio files. If you choose to make an audio CD, which can play in many CD players, you can fit up to 80 minutes of audio per disc. If you're backing up data files, you can burn up to 700MB per disc. Regardless of the content, each CD-RW disc can record at up to 4x speeds.