Since this does not have any resistors or other connections inside for the data lines, this won't work for charging an iPhone, iPod or iPad or other device which expects some sort of resistance on the D+ and D- connections. It does, however, work great forArduinos,BeagleBones,Raspberry Pis, many generic cellphones & Android devices, as well as most other USB-powered gadgets.
There is no regulator or voltage protection in this adapter cable. If you plug in a 9V or 12V power supply in, you could destroy something expecting only ~5V so be very careful!
Cable length from USB end to barrel jack end: 190.5mm / 7.5in