More than five years since their last group release, three members of SS501 are back.

On Wednesday, CI Ent revealed the newly coined Double S 301. Composed of three members of SS501, the new music will be the first collaborative release from members of the iconic 2000's group since 2009.

Although the members faces were not revealed in teaser images, CI Ent teased "U R Man Is Back," alluding to the 2008 hit song by SS501 project unit formed by Heo Young Saeng, Kim Kyu Jong, and Kim Hyung Jun.

Kim Hyung Jun and Heo Young Saeng are represented by CI Ent, while Kim Kyu Jong is currently signed to B2M Entertainment.

CI Ent did not yet announce Double S 301's upcoming promotional calendar.

The name, Double S 301, is the transcribed pronunciation of SS501, altered to represent the group's member loss.

Double S 301 is also a nod to SS501's official fanclub, Triple S. 

SS501 leader Kim Hyun Joong and power vocal Park Jungmin are absent from the promotions.

Kim, a successful actor and solo singer in his own right, is currently serving in the South Korean military while amidst a court case determining custody of his child.

Park is also currently serving in the military, and has released numerous solo albums since the group's hiatus in 2010. He also has pursued an acting career, and appeared in multiple Korean and Japanese dramas.

SS501 debuted under DSP Media in 2005. The group rose to fame as international stars following Kim Hyun Joong's role in "Boys Over Flowers," and SS501's "Because I'm Stupid" is one of the most recognized songs from the hit drama's soundtrack.

The group went on hiatus in 2010, but never formally disbanded and the members have collaborated in the past few years on a variety of performances. 

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