Bose SoundLink Revolve (Series II) Portable Bluetooth Speaker Wireless Water-Resistant Speaker with 360 Sound, Black - ASTONISHINGLY LOUD. SURPRISINGLY SMALL: This small, portable wireless speaker is engineered to deliver true 360 sound for consistent, uniform coverage - IMPROVED BATTERY LIFE: With up to 13 hours from a rechargeable lithium-ion battery, you get more play time than the original SoundLink Revolve speaker. Charging is easy via the Micro-B USB port - DURABLE PORTABLE SPEAKER: SoundLink Revolve II is dust and water resistant (IP55 rating), so it will stand up to splashes by the pool - BUILT-IN MICROPHONE: Take calls and access your devices default voice assistant right from the bluetooth speaker. Or connect the speaker to an Amazon Alexa-enabled device, like the Echo Dot, for even more hands-free control of your music - EASY CONNECT: Voice prompts talk you through pairing your device to this Bluetooth speaker. Multi-connect lets you pair two devices at one time and easily switch between them for complete control of the music - BOSE CONNECT APP: Easily manage Bluetooth connections, unlock features and access future software updates through the Bose Connect app - BOSE SIMPLESYNC TECHNOLOGY: SimpleSync pairs your Bose SoundLink Revolve II Bluetooth Speaker to compatible Bose products for sound that follows you from room to room. Away from your phone? Press and hold the Bluetooth button on each device to sync their sound. Already got a group going? Link by pressing the Action button to connect at a moments notice.