Designed with LEDUP’s unique new technology, these LED icicles are the most reliable of its kind in industry. The LED icicle strings stay lit even one or more LED failed on the string. Individual LED bulbs can be changed easily. Up to 90% Energy saved. Longer average rated lifetime. Cool to touch, low working voltage and current, much less chance of fire or electrical shock. Rugged, not easy to break. 4in bulb spacing. Add sets together for a longer length. Plug and end connector: two-wire, non-polarized. Ambient operating temperature: -40­°C ~+75°C. For Indoor or outdoor use.