Skullcandy Rail In-Ear Wireless Bone Colour Earbuds with Skull-iQ Smart Feature Technology is a powerful technology that enables over-the-air upgrades via the Skull-iQ App. It also runs innovative voice features, which are available in multiple language options. Hands-Free Voice Control for iOS and Android. Prompt a multitude of media apps including Alexa, Spotify and more. Firmware upgrades through the Skull-iQ app. Voice command and prompts provided in multiple language options. Rail lets you breathe easy with a whopping 42 hours of total battery and technology built-in. Plus, Multipoint Pairing lets you connect your earbuds to two devices simultaneously. Rail will switch between devices seamlessly without the need to re-pair. Battery life = 42+ hours - 9+ hours in the bud, 33 hours in the case. USB-C enabled Rapid Charge (10 min = 2 hours). Rail features drivers that have been selected and expertly tuned, in combination with dual Clear Voice Smart Mics, which use A.I. to isolate the speaker’s voice and reduce background noise. Plus, Personal Sound by Mimi lets you custom-tune the sound to your individual hearing through the Skullcandy App. A Capacitive Touch Control on each earbud makes adjustments easy and intuitive. You can even set up your earbuds exactly how you want them with customizable user interface settings in the Skull-iQ App.