Outdoor Tech OT3200 Tuis - Premium Wireless Bluetooth 4.0 Headphones (Grey) 40Mm drivers deliver our most premium hi-fi full range of clear sound, wirelessly. Connectivity Technology: Wired/Wireless Connect to any Bluetooth-enabled device with easy one-touch pairing External controls allow you to adjust volume, change tracks, play/pause and answer calls Rechargeable lithium-ion battery Built-in microphone