Seventeen members 'turnt up' at 'Knowing Brothers's studio.

On August 10, the 13-member boy group guested on the JTBC variety show for the first time since their debut. Throughout the episode, audiences gasped and 'LOL-ed' as almost all of the member took turns showcasing their amazing variety skills with athletic, musical, and other abilities.

For example, member Joshua stunned everyone by walking perfectly on his hands; 'genius composer' Woozi played the soothing clarinet, and leader S.Coups -- well-known for his strength -- foot-wrestled with Kang Ho Dong!

In addition to these talents, other members sang a heartfelt ballad, showed off their 'aegyo', rapped freestyle, and more.

Check out all the videos above and below!