WHAT IT DOES... the extension cable is made to accommodate those who need to remotely control the camera shutter over a longer than normal distance from their camera. WHERE IT CONNECTS... The extension cable has a "male" end connector and a "female" end connector. Simply plug the male 2.5mm TRS connector of your E3 remote into the female end of the extension cord. The male end of the extension cord then plugs into the female E3 receptacle on your camera.