Configuration and observed properties of the sky patches. We divided the eROSITA DE sky into five parts as listed in Table 3. The hatched gray regions in the count-rate histogram show the level of the particle background. We converted count rates into surface brightness assuming a power-law model S ∝ E^−Γ with Γ = 2 and absorption as in Table 3. The surface brightness and flux estimations use the ECFs reported in Table 2.