This 3m oxygen free copper cable for use on Sennheiser headphones fits into each side of the headphones via two integral 2-pole, push-fit connectors, colour coded, red (RH) and black (LH). The cable fits the following models:HD 250 II, HD 440 II, HD 450 II, HD 480 II ,HD 520 II, HD 530 II, HD 540 II, HD 580 . It will also fit most earlier models of headphones with a detachable cable. It comes with a standard 3.5mm stereo jack plug and 379740FC adapter.