If there is a substantial change in the interest rate, the installments of non-indexed loans can change considerably at each review, but in between the installments remain unchanged. Thus, it must always be borne in mind when taking out a loan that installments can increase considerably if there are great interest rate changes between review periods.
In the Loan Calculator, you can view the estimated installments of non-indexed loans and the development of the principal. You can also enter an interest rate of your choice there to see what the effect would be if interest rates rise or fall.