clc's third ep "refresh" and its lead single "high heels" were released on february 29, 2016. this marked the addition of two new members: elkie chong and kwon eunbin, a cube entertainment trainee who was also participating in mnet's girl group survival show "produce 101" at the time. cube entertainment stated that eunbin had been part of the group's original lineup, but was dropped following delays in production of the group's debut album. due to "produce 101" contractual restrictions, eunbin was not able to promote the single "high heels" on music shows or other broadcasts, nor appear in the single's music video. the agency planned for eunbin to join promotions in the event that she was eliminated from the show, or else to postpone her activities as part of the group until after "produce 101" promotions if she was a winner. on february 29, a short version of the "high heels" music video that included elkie but omitted eunbin was released. the full version of the music video, including eunbin, was released on march 21.