The Bluetooth audio adapter adopts the of Bluetooth audio technology standard LE Audio,taking full advantage of the technical advantages of low-power Bluetooth wireless communication; The Bluetooth audio adapter uses the -quality,low-power audio decoder LC3,which is more efficient, lower power consumption,and shorter delay time; Bluetooth audio transmitter and receiver utilize broadcast audio technology, allowing you to share audio and connect with others. After conducting numerous tests,we have found that our audio adapter can link more than 50 receivers with just one transmitter; Automatic connection upon startup,with support for volume increase and decrease at both the transmitter and receiver ends.The transmitter can also support audio input of AUX or USB C,accompanied by LED lights. Bluetooth-Compatible V5.4,ultra-low power consumption The transmitter and receiver have built-in batteries,which can be used for 12 hours and fully meet your occasions. Bluetooth version:V5.4 Working frequency band: 2.402GHz -2.480GHz Power level: Power level 2 (Class I1) Sound delay: Less than 20ms Power supply mode: built-in battery, 250mAh Charging interface: USB DC 5V type-C charging interface Applicable distance: 15M (no obstruction) Working current: Less than 20mA Working hours: 10H Audio input : 3.5MM audio interface/USB type-C interface NOTE: Applicable equipment Equipment with 3.5MM audio output and USB audio output functions, (Such as: TV PC,MP3,CD and other equipment). Receiver applicable eq ipment Speakers and other a idio equipment with AL input interface. Colour:Black Material:ABS Package Contents: 1 x Transmitter 2 x Receiver 3 x 3.5 audio cable 1 x Type-C charging cable Only the above package content, other products are not included. Note: Light reflection 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.