What is the difference between C7 and C9 bulbs? - YouTube
C7/C9 Candelabra Purple Christmas Light Bulbs Sold by Lee Display
UL Listed Box of 25 C9 Led Replacement Bulbs,3 SMD LEDs in Each C9 Dimmable Lights Bulb for Outdoor Christmas String Lights,Full Waterproof and Break Resistant(Sun Warm White) - Walmart.com
Christmas Lights Visual Guide
C9 Red Triple Dipped Transparent Bulbs - Wintergreen Corporation
MIK Solutions C9 Christmas Lights LED Bulb (Pack of 500) Soft Warm White Replacement Christmas Light Bulbs Faceted Retrofit Candle Shape Commercial Grade E17 Socket Roof Lights Bulbs - Amazon.com