The Amazon Echo Buds (2nd Gen) portable Bluetooth wireless noise canceling sports earphones have a isolating ear-insert design. These iPod/cellphone-centric earphones can be used with the noise canceling feature turned on or off, and are intended for use with iPods, iPads, some other cell phones, as well as standard audio devices, and have a claimed reception range of around 33 feet and are intended for use with Bluetooth enabled audio devices including cell phones, as well as standard audio devices. The earphones have an inline microphone and inline remote with xxmusic player function, and call connect/disconnect controls. Additional features include a Either earpiece can be used alone for one ear monitoring of Bluetooth streamed audio and telephone communications. Charging/carrying case has built-in rechargeable battery that the manufacturer claims can be used to recharge the earphone batteries for an additional 10 hrs. of playtime for a total of 15 hrs. with ANC on OR for an additional 13 hrs. of playtime for a total of 19.5 hrs. with ANC off. Wireless charging case compatible with Qi-certified wireless charging pads. Manufacturer claims seat and water resistance (IPX4). Free Alexa app download for Apple and Android devices adds additional features. The headphone noise cancellation control default setting switches between ANC and ambient sound monitor (Pass-through) modes by touch control on either earbud; the default settings can be customized using the app to enable or disable this touch control feature. Has touch control for music player transport, call connect/disconnect, noise cancellation on/off , digital voice assistant activation which can be customized in the Alexa app. Pauses music when at least one earphone is taken out of ear and resumes when at least on is put back in. Alexa voice control can be voice activated using the "Alexa" wakeup phrase; is only available when the mobile device has an Alexa app download and is WiFi or cellular data connected to the Internet. Supports Google Assistant or Siri digital voice assistants when used with Bluetooth connected devices that have those features. Amazon Alexa app shows earphone battery level. Has quick charge feature: 15 min of charging will provide up to 2 hrs. of playtime. Works with all Bluetooth audio devices, but some features (Alexa voice control, changing the touch control options - monitor sound level, tonal balance equalizer adjustment, and Ear Tip Fit Test) are not available unless used with a mobile device with operating systems Android 6.0 or iOS 12 or later with the Amazon Alexa app installed. The Echo Buds (2nd Gen) comes with 4 pairs of ear pieces in various sizes, two pairs of earbowl supports (wing tips) in various sizes, USB-C charging cable, charging cradle/recharger battery/carrying case, Quick Start Guide and is covered by a 12-month parts/12-month labor warranty.