【Battery Replaceable】GUOER G8 Wireless Bluetooth Headset With Backup Battery. Extra battery for free. Unique and superior design, 150hours ×2 stand by time double battery configuration, supplying your battery power anytime and everywhere meet your high demand for work and entertainment. 【Universally Compatibility】You can pair with 2 different Bluetooth devices simultaneously. Multipoint technology allows connection to multiple headsets make sure you can\'t miss any phone calls. Super easy and fast paring with Bluetooth enabled devices such as apple, Android, and Other Leading Smartphones. 【Long-lasting Battery Life】The built-in lithium-ion battery provides up to 5 days. Up to 4-6 hours talking time enjoyment of music for up to 5 hours and 150 hours stand-by with a quick charge of only 1.5 hours. 【High Voice Quality】Clear Stereo Sound, Built-in noise reduction and echo cancellation technology, intelligent filter ambient noise, make it clearer in calling. Comfortably fits either ear (Bluetooth headset good for left or right wearing) 【Comfort And Convenience】Ultralight and comfortable design, ergonomically-shaped in-ear plugs and ear loops brings comfortable and no heavy feeling even after long-time wearing. The ear hook can protect headset far from unpredictable falling out damage.