GP series: GP328PLUS, GP338PLUS, GP339PLUS, GP344, GP344R, GP366R, GP388, GP388R, GP644, GP688. Earpiece Headset Mic for Motorola Radio GP328Plus GP338Plus GP344 GP388 EX500. 1 x Earpiece Headset. - Hidden microphone at the end of the PTT, convenient to transmit.
eBay