With Pioneer SEC-E221BT Wireless In-ear Headphones get rid of the shackles of wire, through the transmission chip in series, to achieve the vocal integration of two mono headphones conversion. Free to choose single/binaural wear, and left and right headphones can be used independently. Office call to release your hands, make the call convenient and safe. In TWS mode, you can listen to music in both ears. When you speak, you can only hear the left ear. Wireless freedom more freedom, enjoy wireless stereo (Left and right headphones can be used separately). One-piece mini-box, metal charging contact design, the box provides an additional 26 hours of monaural life. Enjoy anytime, anywhere, smart black technology escort you. Simple storage, admission can charge the headset. The box provides extra ears for 26 hours of battery life.