They are usually round of reasonably uniform size at around 2.75 inches or 7 cm across. They can have from 3 to 160 protruding knob shapes on the surface. These carved stone balls are nearly all have been found in north-east Scotland, the majority in Aberdeenshire. As portable objects, they are straightforward to transport and have been found on Iona, Skye, Harris, Uist, Lewis, Arran, Hawick, Wigtownshire, and fifteen from Orkney. A similar distribution to that of Pictish symbols led to the early suggestion that carved stone balls are Pictish artifacts. However, examples have been found in Ireland and England.