YCS Basics 6 Inch 2.5mm 4 Conductor Male to 3.5mm Female 4 Conductor Cable For TRRS Devices Only Will Not Work With 2.5mm TRS Home / Office Phones One 2.5mm TRRS (Tip, Ring, Ring, Sleeve) 4 Conductor / 4 Pole male connector (3 black rings) One 3.5mm TRRS (Tip, Ring, Ring, Sleeve) 4 Conductor / 4 Pole female connector (3 black rings) Adapter cable allows you to use a 3.5mm TRRS stereo headset or headphones with built-in-microphone with mobile devices that use a 2.5mm TRRS plug that are wired for the CTIA/AHJ configuration Cable has a 1:1 pin configuration and will NOT work with older mobile devices wired for the OMTP configuration. If your mobile device takes a 2.5mm TRS connection for use with mono headsets, this cable will NOT work. This adapter is NOT designed to work with gaming headsets/controllers or cordless/home phones that accept a 2.5mm connection.