1、Dual Modes and Functions: Rich interface design, dual receiving and transmitting modes, rich interfaces, easy switching. The functions include receiving + transmitting + call 3 in 1. 2、Stable Connection: With the latest Bluetooth chip and well designed software, upgrade your old equipment to Bluetooth function without replacement, but also promises to give you a CD like auditory feast. 3、Working Hours: 8h for RX mode, 5h for TX mode. Built in 200mAh Li‑ion battery (included), it can support Bluetooth adapter once fully charged to provide long time use. 4、Intelligent Charging: When in a low battery state, the adapter can be plugged into the power supply for charging while working. Work while charging, allowing you to enjoy more fun. 5、[Universal Compatibility] This Bluetooth 5.1 receiver transmitter is very suitable for home theater, stereo and car speakers, as well as smart phones, and for Android devices.