Fig. (10) All possible parameter-sets α₁, α₂, α₃ for circular 3C-devices with single mirror symmetry from Fig. (4), that have electrical symmetry R_d = R_e. The straight solid black line denotes devices with geometrical 120°-symmetry. The rest of the surface denotes devices without geometrical symmetry but with electrical symmetry. The surface is symmetric: each device right of this line has a complementary device left of this line where contacts and isolating boundaries are swapped. Two examples of such devices are shown and their respective locations on the surface are indicated. The dashed lines denote devices with constant λ_ed and λ_d and thus identical (i.e. constant Hall output signal at fixed supply current, see (31)).