2 in 1 Receiver Transmitter:Turn to Switcher to the "RX" or "TX" position, the device will work in to Wireless Receiver/Transmitter mode. 5.0 version, The signal is more stable and the sound quality is more pleasantPlug and Play: transmission mode: Wired connection, TV, laptop, desktop computer, projector, radio.Wireless connection, headset, speaker. receive mode: devices, mobile phones, laptops, desktop computers, MP3, game consoles. Audio equipment, wired speakersAUX or RCA, home speakers, amplifiers, wired headphones, car speakersHow to Use Connect the device with a 3.5mm interface, press and hold the power switch for 3 seconds. When using the receiving mode, search for B-10S and connect. When using the transmit mode, turn on the headset or speaker, and it will automatically pair. Note that when switching modes, turn off the device firstLong Working Time: Audio Devices built-in rechargeable lithium battery , the working time will last for about 5-8 hours while just need to charge it for 2 hoursNeed to Know: receiver built-in AEC echo cancellation and ANC noise cancellation circuit, compatible, Android, IOS system mobile phone and PAD, and all audio devices. Support AUXSpecification:version: 5.0Size: 135x80x20MMWorking time: 5-8 hoursCharging time: 2 hoursOutput: 3.5MM audio outputPackage Includes:1 x V5.0 Adaptor receiver and transmitter1 x 0.5M USB to micro USB charging cable1 x 3.5mm 0.5M AUX Audio Cable1 x User GuideNote:B-10S Audio Devices doesn't have the built-in microphone. If connected to B-10S as a receiver, the built-in microphone of your wired headset will be disabled. Therefore it won't be able to support any phone calls.