Replacement Vertex / Yaesu VX-451 Listen Only FBI Earpiece - Acoustic Earphone with 3.5mm Connector For Vertex / Yaesu VX-451 Radio - Headset for Security and Surveillance Replacement Vertex / Yaesu VX-451 Listen Only Acoustic Earpiece with 3.5mm Connector Transparent coiled acoustic tube provides clear audio quality in any type of environment Lightweight flexible and skin friendly materials adds comfort for extended wear time The earpiece wraps behind your ear plus the rotating lapel clip works together to give a more secure fit. Low profile design for a stealth look and feel. UpStart Battery Brand. On Sale for a Limited Time!