The Cursed Seal of Sakon and Ukon (Level 1) is Orochimaru's mark, located on the brothers' foreheads and looking like three round dots forming a triangle. When the first level of the seal is activated, like the other seals of the Sound Four, it draws out the bearer's own chakra, giving senjutsu chakra in return. This increases chakra reserves, physical strength, speed, and ninjutsu effectiveness. When activated, the pattern spreads across the entire body with curved lines and spots, enhancing the brothers' combat qualities in all areas.