Designed with LEDUP?s unique new technology, these LED strings are the most reliable of their kind in the industry. The LED strings stay lit even if one or more LED bulbs fail on the string. Individual LED bulbs are easily interchangeable; mix and match different bulbs from other, similarly styled strings or replacement sets. Because of the efficiency of LED lights, you receive up to 90 percent energy savings and a longer average rated lifetime. The lights are cool to the touch and the low working voltage and current lessen the chances of fire or electrical shock.