Mini Speaker for iPhone

Features: 

"* Small and portable, plug and play, no need battery. 
* With both microphone and speaker function for recording and playing sounds. 
* High quality microphone with fine sensibility and excellent recording quality. 
* Mini sized speaker with good loudness and tone. " 
Specifications: 
"* Sensitivity of microphone: -25± 3dB 
* Rated input power of speaker: 0.5W 

* Frequency response of speaker: 1kHz-20kHz