Hytera's Airtube earphone with VOX and PTT.
List of compatible walkies
Hytera:HP505, HP565, HP605, HP685, HP705, HP785, PDC680, PDM680, PTC680, PD605, PD665, PD685, X1e, X1p, Z1p, PT590
Code: 04.2101.003
Code: 69.2101.004
Code: 43.2101.038
Code: 46.2101.010
Code: 56.2101.029
Code: 10.2101.003