f(x) perform at Simply KPop in Shanghai

It has been a while since we last watched f(x)'s performance.

The girls performed with the absence of Sulli in Shanghai, besides performing their latest hit song Rum Pum Pum Pum, they performedElectric Shock too, watch their performance below:

http://www.youtube.com/watch?v=qXpKRvP3NQw

http://www.youtube.com/watch?v=An1g6-8jYxE