The Etymotion BT from Etymotic is an evolution in the Etymotic brand but also in the Evolution of the Bluetooth cable. Utilizing the latest Qualcomm chip the Etymotion BT supports AptX, AptXHD, and AptX LL giving it 24 bit/48khz lossless capabilities. The Etymotion BT is the first of its kind to have a dedicated DAC and headphone Amplifier installed. The AKM AK4331 with Velvet Sound Technology is far superior to the built in solutions and will give the Etymotion BT the edge over the competition in sound quality and volume. This cable is designed for use with the latest Etymotic ER Series earphones and will also work on most other earphones that have MMCX connectors.