Sescom 3.5mm TRRS Line to Mic Audio Recorder Cable with 25dB Attenuation and Headphone Monitoring Tap for Zoom H4N-PRO / H1 designed for portable digital audio recorders and mic preamps with a single output jack. The IPHONE-LN2MIC Y-Splitter cable allows you to do both monitoring and recording from a single output jack. It also features a -25dB L Pad attenuator on the Left audio channels to reduce the Prosumer Line Level output (-10dBV) to your iPhone® mic input sweet spot level. It's the perfect mating cable for Zoom H4N recorders when connecting to any TRRS 3.5mm Mic input wired for Apple standard. Cable is 12" overall. Monitor tap is 6". Note: To hear the mic signal while recording, you need to use a recording software app with a monitoring feature that amplifies and drives the signal to the headphones.