Four Symbols Seal

One of the Uzumaki clan's fūinjutsu. When two Four Symbols Seals are used together, they form the Eight Trigrams Sealing Style. When Minato sealed the Nine-Tailed Demon Fox into Naruto Uzumaki, he left an opening at the space where the two Four Symbols Seals meet, allowing the Nine-Tails' chakra to merge with Naruto's chakra.

Trivia

 * As part of the Uzumaki clan's fūinjutsu, the Four Symbols Seal, the Dead Demon Consuming Seal, and the Eight Trigrams Sealing Style all bear the same spiral mark.
 * According to Killer Bee, this is a high-quality seal and is more durable compared to the Iron Armour Seal that holds the Eight-Tailed Giant Ox.
 * This seal is the opposite of the Reverse Four Symbols Sealing Technique.