1TEAM released a schedule poster on its official SNS channel on July 17 that contains the schedule for the release of the contents of its new digital single "ULLALALI KKOLLAELI."

According to the schedule poster released, starting with the first concept photo on July 22, the second concept photo on July 24, the first teaser of the music video on July 30, and the second teaser of the music video on August 3, the day before its release, will be released sequentially.

In particular, the title track "ULLAELI KKOLLAELI" is a self-composed song by member BC, who can write and compose songs and is at the center of 1TEAM's music, and is expected to be a signal album as a group capable of producing itself.