Electret microphone is a sound- electrical conversion device. It is used in telephones, wireless telephones, mobile phones, ear-telephones, recorders, radio recorders, alarms, voice control toys, voice control switches and more

Note: Check photo below to find the ground

Specifications:

• Size: 4.5  x 2.2  mm
• Directivity: omnidirectional
• Connection: solder type
• Sensitivity: -28 to -58dB
• Standard operating voltage: 3V
• Impedance: 2.2K Ω