TWINKLY App Controlled 105-Count 34.67-ft Multi-Function Color Changing LED Plug-In Christmas String LightsControl the lights remotely with your phone through the Twinkly app Draw and customize the different effects you want on your lights Links up to 2 sets to extend your lights for extravagant effect For indoor outdoor use Features Series Name App Controlled Power Source Electrical outlet Bulb Type LED Bulb Style Dome Light Projector No Bulb Diameter (Millimeters) 5. 0 Musical No Bulb Spacing (Inches) 4. 0 Bulb Finish Crystal Light Color Color changing