The Hytera ES-01 is a receive-only earbud used with ACN-01. This earbud has a 3.5mm plug. This earbud works with the following Hytera portables: BD302i, BD502i, BD552i, BD612i, PD362i, PD402i, PD482i, PD602i, PD662i, PD682i, PD7 iSeries, PD982i, X1i Series, PDC760, TC-320, TC-508. One year manufacturer's warranty.