If you're ready for professional-grade Christmas light displays, OptiCore LED commercial Christmas lights are ready for you. Put simply, these are the most advanced, durable and beautiful commercial LED Christmas lights around. The traditional C7 and C9 bulb sizes have long been Christmas decorating enthusiasts' favorite. But there was never an LED bulb that could match the color saturation and hue of incandescent vintage Christmas lights. Until now. OptiCore LEDs feature a reflective core design that saturates the bulb lens with gorgeous, brilliant light. And OptiCore bulbs are almost indestructible, made of polycarbonate that's 200 times stronger than glass. For heavy duty, durable outdoor Christmas lights, outside Christmas tree lights, and outside Christmas lights for house, you can't beat the quality, durability and energy-efficiency of OptiCore LED commercial Christmas lights.