For models E40BT and E50BT Connect the first headphone by BT to your mobile device Tap the ShareMe button once Tap the ShareMe button on the 2nd headphones twice ( ! ) The headphones will connect to each other. When changing volume on source device, or BT connected headphones, the volume will only change on THAT headphone ( and in some cases the source device, like iOS devices and newer Android ), not on the one connected via ShareMe. When changing volume on a via-ShareMe-connected headphone ( 2nd ), it will not change volume on source device, or on the BT-connected headphone. To sum up, both headphones have their individual volumes. For Everest models ( not ELITE ). Connect the headphones by BT to your mobile device Put the 2nd device ( speaker, headphones as long as they have Bluetooth ) in "BT discovery mode" Press the ShareMe button on the Everest headphone ( button marked with a little "s" ) The Everest will connect to BT device. (Please note that you may not be able to pair from the Everest to the Everest Elite models, or if you can pair, you may have dropouts in sound). When changing volume on source device, or Everest, the volume will only change on the Everest ( and in some cases the source device, like iOS devices and newer Android ), not on the device connected via ShareMe. When changing volume on via-ShareMe-connected BT device ( 2nd ), it will not change volume on source device or Everest. Please note that it is NOT possible to use ShareMe if you are listening to analog signal via cable. Bot the E-series and the Everest models will switch off the Bluetooth circuits as soon as you insert the audio cable, so re-transmission is not possible.