The Fisher Labs 9720950000 Stereo Headphones with Swivel Ear Cups are compatible with Fisher metal detectors and line tracers. Using headphones improves battery life of the device and prevents the sounds from annoying bystanders. It also allows subtle changes in the sound to be more audible, particularly if searching in a noisy location. This device is to be used with interconnecting cables/headphone cables shorter than three meters. The model 9720950000 offers swivel ear cups and padded earphones, and it utilizes both 1/4 in. stereo and 1/8 in. plugs.