Power devices from a USB port. For small electronics and devices which use a 3.5mm barrel jack for a power cable. Provides 5V DC from USB. Cable length: 80cm Compatibility: For Small Electronics And Devices Which Use A 3.5mm Barrel Jack For A Power Cable Type A Male USB plug to 3.5mm(outer), 1.35mm (inner) male coaxial/barrel plug Adapt your USB port with this cable so you can power small devices and electronics that use a DC barrel plug with 3.5mm outer diameter and 1.35mm inner.