1. Microphone size: 6x2.7mm, speaker size: 15mm 2. Microphone sensitivity: -38dB+/-3dB, speaker sensitivity: 106dB+/-4dB 3. Microphone frequency: 1kHz 4. Microphone impedance: 2.2KOhm, speaker impedance: 110Ohm 5. A remote microphone with a push-to-talk button, you can edit anywhere. 6. The transparent tube connecting the earplugs makes you look like a special agent or bodyguard and protects you from radiation. 7. The earplugs/speakers are close to your ears to keep your conversation private. 8. Cable length (plug and play): 100cm. 9. The length of the cable (PTT to speaker): 108cm. 10. Two-pin standard diameter: 3.5mm stereo ear (thimble). Microphone 2.5 mm stereo (bottom pin). 11. The distance between two needles: 11mm. 12. Suitable for Kenwood KPG27D, KPG29D, KPG48D, KPG49, KPG55D, KPG56D, KPG62D, KPG66D, suitable for Retevis H777, 888s Plus, suitable for HYT TC286,386,2685,3865,668,TC 278, etc.