An internal device for use in an underwater cable may comprise a body having an outer periphery, body being mountable inside the cable with the cable surrounding the outer periphery of the body. The body may include a cutaway portion, a slot, or a dovetail joint. An underwater cable arrangement may comprise an underwater cable and an internal device disposed in the cable with the cable surrounding the device. The underwater cable may include a stress member connected to the internal device by an interference fit or the internal device may include a slot for receiving the stress member. A method of connecting a stress member of an under water cable to an internal device includes forming an interference fit between a region of increased diameter of the stress member and the internal device.