Include Erhu, Gao Hu, Zhong Hu, Low Hu, Falling Hu,Ban Hu,Jing Hu, Coconut Hu, Qu Hu. With noise filtering. First step is choose the frequency at top of screen, then choose the tuning at the middle of the screen. When you pull the string, the pitch will be shown on the panel for the individual string by indicating signal high or low. [Tuner] - Calibrate Piano Sound : Click on an open string then calibrate the sound with your Erhu. Piano Sound A4=442. - A4 Frequency adjustment: choose 428~45