1.10MM speaker unit for calibration in sports. 2.High quality TPE cable, adopts 3.5mm audio interface, convenient for listening to music or watching movies 3.In ear design ensures noise cancellation.Speaker: 10mmSensitivity: 93+-3dBSpeaker Impedance: 15Ω+-15%Frequency Response: 20Hz to 20KHZPLUG: 3.5mmCables length: 1.2m