For the non-engineer among Amazon visitors it would be helpful if such restrictions were highlighted in the product description. Care must be taken, if he has two or three rings in addition to the correct size of the plug (3.5 mm). Smart Phones and Tablets expect the sound input signal on the third ring, which is missing here in the rule. For this micro works well for direct connection to most cameras and camcorders, which in turn would not recognize connector with three rings. One can make the respective opposite compatibility with adapters, but who wants to take a bunch of adapters for mobile use. Then maybe the other way around: the road everything fits right at home and use one adapter for the 2 ring devices.