A steep-edged, often large, domed core with flat based striking platforms, heavily step-flanked around their margins. Both very large and smaller varieties are found commonly on Pleistocene sites in most areas of Australia and on some mid-Holocene sites and they are considered characteristic of the Australian Core Tool and Scraper tradition. They were chopping tools mainly used in wood-working. The step-flaking could have resulted from repeated striking to remove flakes.