FiiO ROCKY (E02i) is a headphone amplifier designed for Smart Phones. Specifically the iPhone series, which means it can support all the line-control headphone functions of the iPhone.

FiiO ROCKY E20i can also support the Samsung Galaxy series of devices and the HTC One series Android phone, but they will be limited to basic functions like amplify, play/pause, answer/hang up and refuse calls. Volume control, forward/rewind and fast forward / rewind functions may not be available on these phones.

Model Name ROCKY E02i Weight 27 g Audio Input iPhone headphone out Volume Control Line Control in iPhone Headphone Drive ability 16-100 ohms Battery Capacity > 100 mAh Output Power >75 mW@32 ohm THD <0.005%@1KHz Frequency Response 10Hz~30KHz Input Sensitivity < 1 Vrms Crosstalk > 68 dB@1KHz Gain >4 dB MAX output voltage >4.3 Vp-p Color Available Black/Silver Dimensions 23.3 x 57.3 x 15.3 mm Headphone output 3.5mm stereo Jack Bass Boost YES Power input USB 5V/500mA Battery Life > 8 Hours Charging Time < 90 Mins Output Impedance <0.3 ohm Signal to Noise Ratio >100 dB MAX input Level > 1 Vrms Channel imbalance < 0.05 dB Bass Boost Range > 3 dB@100Hz MAX output current > 48 mA