You can choose the right-sized stone from the corresponding measurement chart.

Each row of the table represents a particular Taidekivi model, while each column stands for a particular diameter of the object to be covered. Each cell contains a maximum height of the object (in cm), which is possible to be covered by a chosen Taidekivi hollow stone. 

Measure the diameter of the object to be covered. Find the corresponding column. Take the bigger one, if the diameter value lies in between of two neighbour values.

Go from top to bottom through the values in this column and find the first value, that is equal or greater than the height of your object to be covered. 

The row, this cell belongs to, will indicate the Taidekivi stone's diameter needed.