Fully padded Bluetooth headphones which produce crystal-clear sound and are compatible with mobile devices that support Bluetooth. They have a continuous playing time of six to eight hours and have a built-in microphone which allows the user to answer incoming phone calls. The volume and track are able to be changed directly from the headphones and they can be recharged from any USB port or a mains adapter. Opus is nicely presented in an elegant carry case with a Micro-B USB cable and an instruction leaflet.