Toy model RV signal caused by the Zeeman effect from a co-rotating magnetic spot with zero temperature contrast. The signal is calculated for three different field strengths inside the spot (green: 100 G, black: 600 G, and red: 4000 G); for each case three different spot sizes are used (f = 1%,3%, and 10%). Gray dashed lines show an analytical approximation of the scaling using Eq. (2). The dotted line visualizes the 1 m s^-1 limit.