Kamen Rider Faiz (仮面ライダーファイズ, Kamen Raidā Faizu, "Masked Rider Faiz") or SB-555 Faiz (SB standing for Smart Brain) is the main protagonist of Kamen Rider 555. Its gear is the first of the Rider Gears seen in the series. Its motif is the Greek letter phi (Φ).