The previous owners of our house had the forethought to put in some sort of flexible trunking under the block paved drive with what can only be described as place holders for junction boxes / switches at intervals along the driveway, I’d like to put in some lighting down the drive way, probably no more than about 20 small spot lights, low voltage if possible. What cable do I need to try and thread down the underground ‘tube’ for this? The trunking seems to be a rubberised outer layer, with a flexible steel inner btw.