Comes with a USB A socket on one end and a USB A plug on the other. In between is an in-line switch that is rated for 2 Amps. The data lines are not connected through - this is a ground/5V power switch only! The switch is on the positive 5V line. A great match for our USB wall adapters or battery packs. If you have a device that uses the data lines to set the charge rate, this switch may not work, we use it for adding a 'hard power switch' to a Raspberry Pi.