Sony's higher-speed professional variation on DV, it samples at 4:1:1 rate and has 5:1 compression. Audio is selectable between two PCM channels at 16 bit and 48 kHz, or four PCM channels at 12 bit and 32 kHz. Sony introduced a feature with the format that allowed for information such as good and bad takes to be recorded onto a memory chip that is housed inside the cassette.