ROCKTECH Sport Portable Wireless Bluetooth 4.0 Speakers,Water Resistant with 2 X 3W Stero,Enhanced Bass,Built in Mic and 12H Playtime,Pairs with All Bluetooth Devices(Black) Wireless Water-resistant Portable Bluetooth Speaker for Music Streaming via Bluetooth V4.0 Technology and CSR chip set; connects faster, more stable and compatible with most Bluetooth-equipped devices; outstanding connection range of up to 10 meters The 3W X 2 total system power2 high-performance drivers and ultra-small size produce a wide audio spectrum. The newly designed passive radiator could provide strong bass without distortion even at highest volume Built-in microphone: Enables use this Wireless Bluetooth Speaker as a speakerphone, so you can enjoy hands-free calling Built-in rechargeable 3.7V, 3600 mAh lithium-ion polymer battery: Provides extended playback, enables you to stream music for up to 12 hours on a full charge and use it as Emergency Power Bank to charge your mobile via internal rechargeable battery Water-resistant and sand-proof design: Safeguards the subwoofer sound speakers against water submersion, plus dust and other small particles, so you can listen to music both indoors and outdoors