JBL Synchros E40BT, Bluetooth, On-Ear Headphones with JBL Signature Sound, Purebass Performance, Wireless Shareme Music Sharing and a Superior Fit, Black JBL signature sound with PureBass performance and premium 40mm drivers deliver full spectrum sound with uninhibited clarity and powerful bass. Connectivity Technology: Wireless Bluetooth enabled technology for wireless calling and music play. Built-in Share Me technology allows you to share your content with another set of headphones, simultaneously Ear-cup-based microphone with echo-cancelation technology allows for hands-free calling with a pure connection to your wireless device for clear, hands free calling Built-in, USB rechargeable lithium-ion battery provides 16 hours of uninterrupted listening. And when the battery dies, the included aux cable allows for passive listening Ergonomic headband and protein leather ear-cushions provide an ultra-comfortable fit and effective noise isolation