[Comfortable and Multifunctional] - The ergonomically designed Avantree D4169’s in-ear and over-ear headphones are to provide all-day comfort. Both wireless headphones have built-in microphones and along with the Bluetooth transmitter can be used with other devices. Use either of the headphones to make a call, listen to your favorite podcast, music, or sporting event, when connected to any Bluetooth-equipped device (mobile phone, laptop). [Hassle-free Setup & Long Playtimes] - The headphones and transmitters are factory pre-paired, so the setup is a snap. Once you power on the transmitter and headphones, they’ll connect right away – every time. The in-ear headphones provide up to 20 hours when fully charged, while the over-ear headphone's playtime is up to 40 hours. [Personalized Audio] - The D4169 allows you to adjust each headphone’s volume level independently, letting you avoid remote wrestling or clashes over the volume level. Those individuals experiencing hearing can now increase their volume levels without affecting their partners’ TV experience. [Dual Link - Simultaneous Audio] - Dual Link allows audio to be played through both pairs of wireless headphones simultaneously. However, either headphone can function independently in case only one person is watching TV. Your partner or friend can join you at any time without any audio interruption for you. [Ultimate Wireless TV Watching Set] - The Avantree D4169 contains a Bluetooth Class 1 transmitter and two pre-paired headphones: one (1) in-ear and one (1) over-ear. The aptX LL transmitter delivers <40 ms latency for no lip-sync delay, And, the provided Optical, AUX, and RCA input cables make it compatible with any smart or non-smart TV’s audio output jack.