2 pin to 3.5 mm adapter, Earphone Headphone Plug | Earphone Accessories | 3.5mm 3.5mm | Iem Adapter - Audio & Video Cables - Aliexpress, Amazon.com: Retevis Earpiece Adapter for Talkie,2 Pin to 3.5mm Headset Adapter Only Compatible RT22 RT21 RT27 RT7 H-777 H777S RT18 RT19 RT22S(Not Fit for Other Brand) 2 Way Radio (5 Pack) :