Features:
Bluetooth  and FM stereo connection
USB phone charging 
Convenient for taking calls while driving
Powered through your cars lighter socket 
Bluetooth support allows for streaming audio content between the transmitter and your phone
Built in hi quality mic
One button control for answering, dialing and hanging up calls
With USB and micro SD ports you have 
Specifications:
Bluetooth Version: Bluetooth V4.1 + EDR
Bluetooth music editing: A2DP
Sensitivity: -42dB +/- 3dB
Frequency: 2402-2480 GHZ
Operating voltage: 5V +/- 0.5
FM frequency band: 87.5-108MHz
USB output: Maximum 2.1A total
Effective distance: 10 meters
Dimensions: 14.5 x 5 x 3.5 cm