Christmas lights string by Aca length 2m, with 20 led lights, with a thickness of 2mm. They are black cable and emit warm white light, which is measured on the Kelvin scale with values from 2400K to 3800K. The tones of warm white are more yellow 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 adjust their operating time with the included timer.. They operate with batteries.