Surround yourself with your favorite music rendered with acoustic brilliance on the fashionable, black JBL E40BTBLK Synchros E40BT Bluetooth Over Ear Headset. These JBL headphones contain enormous 40mm drivers that produce audio frequencies from 20hz to 20kHz with uncanny accuracy. The PureBass performance of the headset beautifully complements the drivers' delivery with rich, deep base, giving you the greatest music listening experience ever. These headphones are equipped with Bluetooth connectivity that lets you wirelessly connect to other devices, so you can enjoy your favorite music anytime, anywhere. The over the ear headphones have a built in rechargeable Lithium Ion battery that will give you 16 hours of play time. If you do run out of charge, you need not put them away dejectedly; simply connect the included aux cable and continue listening. The headphones are built to blend with your lifestyle and feature best fitting headband, 360 degree swivel hinges, and soft ear cups that will make your time with music comfortable and captivating.