C9 Warm White Smooth OptiCore LED Christmas Light Bulbs
Wintergreen Lighting OptiCore Blue LED C9 String Light Bulbs in the String Light Bulbs & Fuses department at Lowes.com
C9 LED Bulbs - Diamond Faceted Replacement Christmas Light Bulbs - 8 Lumens | Super Bright LEDs
Amazon.com : Wintergreen Lighting 25 ft C9 Color Changing Lights LED Light Bulb Color Changing String Lights, 25 Christmas Lights on Green Wire : Patio, Lawn & Garden