We locate configurations where Riesz potential functions on two circles in two different parallel planes are constant. We use such result to find maximal and minimal polarization constants and configurations of two circles in two different parallel planes.

**Reference
**N. Bosuwan (2020) Constant Generalized Riesz Potential Functions and Polarization Optimality Problems, Thai Journal of Mathematics, Vol. 18, pp. 1841-1855.