Reinders Holiday Lighting - Bulb sizes seem to be a confusing topic for those new to the industry. Admittedly, there are a lot to choose from and it can get overwhelming, so
LED Bulbs: Their shapes, sizes, and bases – Christmas Light Source
What is the difference between C7 and C9 Christmas Bulbs? – Christmas Light Source
LED Christmas Lights
CSA Listed Box of 25 C7 Led Replacement Bulbs,Commercial Grade 2 SMD LEDs in Each Lights C7 Dimmable Led Bulb for Outdoor Christmas String Light,Full Waterproof and Break Resistant(Blue Color) : Amazon.ca:
Holiday Lighting Outlet LED C7 Blue Replacement Christmas Light Bulbs, Commercial Grade, 3 Diode (Led's) in Each Bulb. Fits in E12 Sockets. Pack of 25 Bulbs, Fluorescent & Neon Tubes - Amazon Canada
Wintergreen Lighting OptiCore C9 LED Pink Faceted Christmas Light Bulbs (25-Pack) 72664 - The Home Depot
Joiedomi LED C6 Multicolor Christmas Lights,150 Counts 50.6FT String Lights Outdoor Indoor, Connectable Green Wire Christmas Trees Lights,Small Xmas Decorative Lights for Holiday : Amazon.ca: Tools & Home Improvement
Christmas LED String Lights Guide | Bright Ideas by PartyLights.com