National Tree 70 Bulb Indoor/Outdoor Dual LED Lights, Add On Set (LS11-802-70) ADD-ON light string set includes 70-bulb low voltage LED Dual Color lights Requires one STARTER SET for operation, model # LS11-801-70 (sold separately) Up to seven ADD-ON sets can be attached to STARTER SET Lights change from soft white to multicolor with the press of a switch For indoor use only