It can turn the combo port into two distinct ports, one 3.5mm headphone jack + one 3.5mm microphone port, a perfect solution for online gaming or use with VOIP applications (Skype, chat programs). As there is no accepted industry-wide standard for 4-Pole (4 position) TRRS plugs & sockets, many manufacturers have developed their products with different pin layouts (eg: Nokia, Android and Apple devices).
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