Jamieson, Fausset and Brown on Jeremiah 18:3

3. wheels--literally, "on both stones." The potter's horizontal lathe consisted of two round plates, the lower one larger, the upper smaller; of stone originally, but afterwards of wood. On the upper the potter moulded the clay into what shapes he pleased. They are found represented in Egyptian remains. In Ex 1:16 alone is the Hebrew word found elsewhere, but in a different sense.