The four balanced-armature driver  design of the W40 will take your listening to an entirely new level. The  award-winning sound of the W40 features a beautifully-flat frequency response  with articulate lows, precise mid-range, sparkling highs, and performance that  is perfect for recorded and mastered music. The Westone Audio W40 is the ideal  first earphone for those music lovers and critical listeners looking to get the  absolute most from their listening experiences. Ideal for all personal audio  and video devices.
 Proprietary Ear Tip Technology:  60 years of experience designing products for the ear, has resulted in a  universal-fit earpiece that is compact, low-profile, lightweight, and extremely  comfortable. Our proprietary eartips enhance the performance of the W40 by  ensuring a great fit and seal, right out of the box.
Balanced-Armature  Drivers
  Westone Audio’s proprietary balanced-armature  drivers provide enhanced sonic detail and frequency range that extends well  beyond other in-ear solutions.
Westone  Audio Bluetooth Cable
  Full-resolution Bluetooth Cable uses aptX®  technology to deliver extraordinary detail, clarity, and a dynamic soundstage  that has to be heard to be appreciated. The Westone Audio Bluetooth Cable  features; 8 hours of battery life, a 10 meter/ 32 foot range, has a water and  dust resistant IPX-4 rating, and features our exclusive MMCX Audio® connectors,  which allows the Bluetooth Cable to be used with any custom-fit or  universal-fit earpiece.
High  Definition Silver MMCX® Cable
  Westone Audio’s High-Definition Silver MMCX® Cable  features four strands of low-resistance, pure-silver plated copper alloy,  braided around a center strengthening core. Low resistance silver-plated copper  wire improves electrical conductivity, providing extraordinary clarity and  detailed sound reproduction.