Please note that ATA66 / ATA100 / ATA 133 cables are all essentially the same. As such ATA66 cables work fine for ATA100/ATA133 etc and vice versa. Higher speed cables also work for lower speeds. The rating of the cable however may have an impact on quality. A cable only marked ATA66 may be slightly lower quality than a cable marked ATA133. This is because the ATA133 cable is newer.