Point Source Audio CM-i3-PH - Dual In-Ear Intercom Headset (3.5mm Mini)3. 5mm Mini cable for use with compatible mobile phone and computer applications. The CM i3 is the world's first modular intercom headset. This intercom headset has a patent pending slim line design that allows for three listening modes.Rather than having to remove the entire headset to check environmental sounds or interact with others, simply remove one or both earphones to exit the listening mode or monitor a mix of feed audio and surrounding