I.O.I's sub-unit sings 'Whatta Man(Good Man)' in new teaser video

I.O.I transforms into ultimate girlcrush in new teaser video for 'Whatta Man(Good Man)'.

The girls all dresses in black while showing their charisma through a powerful choreography, taken everyone by surprise as this is totally different from their cutesy debut concept.

The song will be released on August 9th. Meanwhile, check out the video below