MAMAMOO's Solar and Moon Byul have dropped their music video teaser for "Promise U".

In the MV teaser, Solar and Moon Byul are under beautiful blue skies as they sit by the pool. "Promise U" is an upbeat ballad with an acoustic guitar accompaniment about promising to forget someone, and it's set to drop on July 28 KST.

Watch Solar and Moon Byul's "Promise U" MV teaser above, and let us know what you think in the comments below.