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: 04.1801.011
Code: 43.2101.086
Code: 43.2101.018
Code: 80.2101.001
Code: 63.2101.059
Code: 63.2101.043