Specifications:It supports audio input audio equipment， wireless audio transmission.Built-AEC echo cancellation and noise cancellation circuit ANC， gorgeous stereo sound more pure.Built-in enhanced signal transmission circuit connected faster and more stable tone continues.Compatible with lossless audio formats.Support AUX OUT.Automatic memory connectivity， operating more simple， more convenient connection.Built-in battery， long life time.Bluetooth 4.1， low power consumption.Live voice prompts， simple and clear.For smart compatible， for Android， IOS phone system and PAD， and all Bluetooth audio devices.Simultaneously connect two phones.mini Bluetooth 4.1 audio receiver A2DP wireless adapter for home audio music streaming sound system & Bluetooth car kits with 3.5 mm stereo output for smartphones & tablets.Type: Wifi AdapterMain Color: BlackBluetooth Version: 4.1Compatibility: for Android System， Mobile Phone or Tablet， IOS System， and all Bluetooth Audio DevicesTransmission Distance: > 20M (Open Area)Operating Current: 18-28MABattery Standard: 300MAWorking Hours: 8-10HCharging Time: 3HOutput Connections: 3.5mm Stereo JackSize: 110mm x 62mm x 18mm/4.33" x 2.44" x 0.71" (Approx.)Notes:Due to the light and screen setting difference， the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes: 1 x Audio Receiver1 x USB Charging Cable1 x 3.5mm Audio Cable1 x Audio Adapter Cable1 x User Manual