Not fit for cell phone. Feature: Air duct design principle， is to prevent electromagnetic radiation. Sound through the air duct， filter out the voice of the volume which is too strong and endanger human body health. So this one is no like other headphone wiht so loud sound. Long time wearing more comfortable， ear won't pain， and not easy to fall off. Speaker Size: 15mm Sensitivity: 102dB ± 2dB @ 1Kz Impedance: 32Ω Power: 5mW Connector: Life time:12000times(put in an take out) According to radio models，different connector available Mic: Dimension:6.0 x 2.7 mm Sensitivity: -38db Impedance: 2.2K Ralated current: 100mAh Matching walkie-talkie type: Kenwood TH272G/372G，TK3130ProTalk Series，TK313Free Talk series， TK220/320/240/208/360/370…etc Package include: 1 x Headsert Earphone 1 x XSSML