PRO AUDIO TUBE The T-2030 is a 3.5mm threaded plug, 40 inch cord, plugs into 3.5mm threaded jack located on the Shoulder Mic Cable where the cable connects to the radio. The T Series Acoustic Tube Earpiece for audio only communication comes with two open ear inserts-left and right, a clear acoustic tube, a black acoustic tube and a patented clear and black ear frame. See history from EH-T2030