The radial Electric field (Er) is an important parameter of the Scrape-Off Layer (SOL). Via poloidal E¥B drift, it directly influences poloidal motion of main ions and impurities, contributes to the parallel ion Pfirsch-Schlüter flow and toroidal momentum in the SOL, and affects asymmetries between outer and inner divertors. The magnitude of Er in the SOL, at the same time, is a good indication of perpendicular and parallel transport processes in the SOL and divertor, including the formation of the Debye sheath at the targets.