Yaesu Original MH-34B4B Speaker Microphone w/Swivel Clip & 3.5 mm Earpiece Audio Jack Hand Speaker Microphone w/ Swivel Clip & 3.5 mm Earpiece Audio Jack Speaker Diameter: 32 mm Speaker Audio input: 0.5W Microphone type: Electret Condenser - Microphone Impedance: 22K ohms Speaker Impedance: 8 ohms