Clear sound; the impedance of the walkie talkie headsets speaker is 32 ohms; low impedance design brings users a clear sound quality experience ^^ VOX function; push the button to turn on the VOX of the ear piece for walkie-talkies; it should be noted that you need to open the VOX of the two way radios firstly ^^ Coil design; radio earpiece with coil wire design; can meet the needs of people with different heights or body types for the length of the wire ^^ Acoustic tube; 2 way radio earpiece with mic makes your communication more private; suitable for using in some private occasions; such as security guards; police; eavesdropping; secret agents ^^ K head 2 pin; widely compatible with most 2 way radio models; such as Retevis RT22 RT21 H-777 RT68 RT19 RT22S H-777S RT27 RT28 two way radios; compatible with Baofeng UV-5R 888S Arcshell Kenwood Pxton Samcom Two Way Radio etc