The E1-2W2CM131-CM Two Wire Earphone Kit for ICOM /F4101 2-Way Radios by Otto Engineering is for monitoring audio. It can be used in various environments for applications such as, hotel personnel, event coordinators, retail stores, security at airports, crowd control at conventions, concerts, and more. The kit consists of two cables: one that has a lightweight earphone, rubber eartip, acoustic tube, acoustic tube adapter; and one that has a combined push-to-talk switch and microphone, and both terminate in the radio accessory connector. The low-profile, flexible, transparent acoustic tube, is built with Kevlar reinforced cables for added strength. The molded 2-way radio connector cable is built of a proprietary alloy of rugged tensile strength. This kit is designed to deliver clear audio that goes unnoticed by others.