... effect, use DIGITAL and PLL phase lock technology. 2,With LCD screen display,clear and convenient to adjust the tuning frequency ... charger or computer USB 5V charger(optional). 8,works with all 3.5mm output audio device: such as ipad, ... frequency,never be drifting.*All frequency design,Can avoid conflict with radio interference. Technical parameters: *frequency characteristic:20Hz-20KHz*separating ...