Christmas lights string by Eurolamp length 13.15m, with 200 led lights, with a thickness of 3mm. They are green cable and emit cool white light, which is measured on the Kelvin scale with values from 5000K to 6800K. The tones of cool white are more blue compared to natural light. They have IP44 protection, which means they cannot be penetrated by solid objects larger than one millimeter and also cannot be penetrated by water with high intensity. You can extend their length by connecting them to other bulbs.. They operate with electricity.