Yesterday, BTS photos of 'Superstar K4' contestants Roy Kim and Jung Joon Young had surfaced online.

The CF turned out to be for Cass Light, and all top 12 members of 'Superstar K4' took part in it. The participants sang John Biancale's "Up & Down", singing the line 'Up and down' and explaining at the end that "The taste is up, but the calories are down".

As expected, heartthrobs Jung Joon Young and Roy Kim were at the center of attention. Roy Kim sang a soft ballad while he strummed on his guitar, while Jung Joon Young sang the line in a powerful rock style. Netizens commented, "Jung Joon Young really is a singing Kang Dong Won", "I really like Roy Kim's version", and "Jung Joon Young fits the Cass Light image perfectly".

Check out the CF below!