If you are joining multiple strips of tape lighting, you may need more wire than is included in the kits. This indoor/in-wall rated, two-conductor 18-gauge stranded wire is supplied as a 26.2' (8m) roll.
Two-conductor wire is needed for connecting multiple individual white LED lights, for example, mini lights or downlights. For color-controlled lighting, two-conductor wire can be used only to connect the power supply to the color controller. (All other wiring connections involving color-controlled lighting require four-conductor wire.)
Note that outdoor installations or those in wet locations, like shower enclosures, require the use of outdoor-grade connectors and wire, in addition to outdoor-grade lighting.