Waterproof Sport Bluetooth Speaker, DYJ Outdoor Portable Wireless Bass Subwoofer Sound Speaker with 3600mAh Power Bank/Mic/NFC Function for Travel Bicycle Climbing Camping Hiking Running (Green-1) Wireless water-proof Portable Bluetooth Speaker for Music Streaming via Bluetooth V4.0 Technology, compatible with most Bluetooth-enabled devices Bluetooth speaker 4.0 and CSR chipset connects faster, more stable, compatible with all your Bluetooth-equipped devices, and Outstanding connection range of up to 10 meters 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 Water-proof 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