For Motorola, this earplug type is an alternative to bulky speaker microphones. The miniature earphone keeps conversations private; the thumb size microphone uses a PTT switch and has a maximum tensile strength by utilizing mineral fiber cables to insure reliable service. Lightweight and easy to conceal, the revolving 360-degree clip makes attaching to a shirt or coat easy. This high quality dynamic earphone & electric microphone give your handheld crystal clear audio. SPEAKER UNIT: Speaker Diameter: 15mm; Output level: 72dB; Rated Input Power: 0.1W; Max. Input Power: 0.1W; Output Impedance: 32 ohm. MICROPHONE UNIT: Type of Element: Non-directional electric condenser type; Sensitivity: -58dB; Output Impedance: 1k ohm.