Features:
*  The Bluetooth adapter combines Bluetooth audio transmitter and receiver in one with an 3.5 mm Aux jack. Bluetooth connection is more stable and wireless range is more than 33 feet. Easy to pair and compatible with 99.9% Bluetooth devices. 
* Dual Connection: When used as a Bluetooth transmitter, it can be paired to two Bluetooth receivers such as headphones and speakers simultaneously. When working as a Bluetooth receiver, it can still be paired to two smartphones or tablets, but the receiver can only receive the audio from one of the two paired devices.
* Small Size BUT Long Battery Life ↔ Built-in 280 mAh polymer battery, it can work up to 7 hours when used as a receiver and up to 4 hours as a trasmitter. It also support using while charging.
*  As a Bluetooth Audio Transmitter (TX Mode), turn a non-Bluetooth TV, PC, CD player, iPod, Laptop, Tablet, MP3 / MP4 (including but not limited to) into a Bluetooth transmitter with 3.5mm jack input port. During receiver mode you have full control of the music including play / pausing, track selection, and volume control with buttons on the adapter controls. The adapter can connect to traditional device like wired headphones or speakers so they can receive Bluetooth music direct from phones and tablets.
* Handsfree phone call - this audio transceiver have the built-in microphone. If connected to adapter as a receiver, the built-in microphone of your wired headset will be actived. Therefore it  will be able to support any phone calls.

Parameters:
Charging voltage:5V
Charging time:About 2H
Working time:About 7H
Battery capacity:280mAh
bluetooth Ver.:Version 5.0,10M
bluetooth audio processing:DSP and A2DP
bluetooth frequency:2.402-2.480GHz    
bluetooth MIC effective distance:0.5~2M
bluetooth transmission output power:6dbm