What is the difference between C7 and C9 Christmas Bulbs? - Christmas Light Source Blog
Amazon.com: 25 Feet C7 Led Christmas Light Set with 25 Led Crystal Faceted Strawberry Bulbs, UL Listed Outdoor Christmas String Lights for Patio Deck Roofline Driveways Christmas Decoration (Multicolor)
Wintergreen Lighting OptiCore C7 LED Multi-Color Smooth/Opaque Christmas Light Bulbs (25-Pack) 74041 - The Home Depot