The Flanger FC-20 is the easiest way to send your instruments signal into an iPhone, iPod Touch or iPad. Just plug the FC-20 into the device's headphone jack,your instrument into the FC-20, and connect the output of FC-20 to an amplifier or another device that has line input, like a mixer, keyboard, or a synthesizer. Listen to the sound through headphones and the output jack will automatically mute. The 6.35mm input jack is designed for guitar,bass and also applicable for keyboards, microphones mixers etc. The 6.35mm output jack can be connected to an amplifier. Features 3.5mm stereo headphones jack. The 3.5mm input plug connects to your Iphone. Compatible with Iphone/Ipad apps: effects, tuners, metronomes, tone generators, recorders, amps etc.