The Bell & Howell BH20TWS (True Wireless Stereo) Speaker can be used alone or paired with the built-in True Wireless Stereo technology to create up to 4 hours of rich, robust audio pleasure. The rugged and portable design is great for traveling and outdoor use. Features include, Bluetooth and Auxiliary connectivity, Built-in Lithium-Ion Rechargeable Battery, Built-in Micro SD Card Slot, Built-in Microphone, Easy Access Interface, and Powerful HD Sound.