Features:100% brand new and high quality Adopts advanced bluetooth-compatible 5.0 module, with HiFi high-quality sound effect, built-in noise reduction. Fully compatible automatic matching. One-button mode switching, red light receiving, blue light emitting. Plug and play without driving. No built-in battery, external power supply. Specifications:Bluetooth-compatible Version: v5.0 Bluetooth-compatible protocol: AD2P Transmission signal distance: 10m-15m/33ft-49.2ft Transmission rate: 100 (Mbps) Working frequency: 2.4 (MHz) Interface: 3.5mm AUX/ USB Input voltage: DC/5V Product size: approx 2.5x4.2x1.1cm/0.98x1.65x0.43in Note:Because the product needs to read data when it is turned on, if you need to change the mode, please wait for 1-2 seconds, and do not press the switch quickly. Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.Package includes:1PC x Bluetooth-compatible 5.0 Audio Transmitter Receiver 1PC x AUX Cable 1PC x Instruction Manual