USB audio input: Connect to the USB interface of a computer, Switch base, TV BOX, etc., and directly transmit audio to the transmitter through the USB interface, and wirelely transmit it to a Bluetooth headset or speaker. (Note: No need to plug in audio cable, no driver required)AUX audio input: 3.5MM audio cable is connected to the transmitter, which can input the audio from TV, CD, MP3 and other devices to the transmitter, and wirelely transmit it to the Bluetooth headset or speaker.Support A2DP,AVRCP,AFH,HFP,HSP protocol. The transmitter supports one for two, and the dual-link supports aptX Adaptive.Supports duplex call mode, you can use computer voice to talk while playing games. (Headphones/speakers need to be equipped with call function).Specifications:Bluetooth version: V5.3Input port: USB /AUXTransmiion distance: Greater than 10 metersFrequency range: 2.402GHZ-2.480GHZSupport protocol: A2DP, AVRCPAudio encoding: support aptX Adaptive, aptX HD, aptX LL, aptX, SBCDevice power supply: USB 5VOne for two: Support simultaneous connection of two stereo headsets.Support LL/HD loop switching, provided the product supports HD.Material: Plastic + Metalcolour: blackPackage Contents:1 x USB Wirele Audio Transmitter1 x antennaOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.