1/4" female to 1/8" male stereo adapter - TRS. This is an adapter that converts your quarter inch (1/4" stereo cable down to a 1/8 on eighth / 3.5mm stereo male plug. It has a 1/4" female plug trs on one end and a 3.5mm trs male plug on the opposite. This adapter is great when your headphones have the large cable end and you need to adapt down to the 3.5mm or 1/8" stereo plug. It's also useful for many other applications.