C9 Christmas Lights

C9 LED Christmas lights from The Christmas Light Emporium use an intermediate E17 screw base — the larger of the two standard outdoor bulb sizes and the industry standard for rooflines, gutters, and large-scale architectural outlines. The C9 bulb is larger and more visible at a distance than C7, making it the dominant choice for professional and DIY roofline displays.

What's in This Collection

C9 ProCore® Replacement Bulbs — Sold in packs, for use in C9-compatible stringers. Faceted and smooth lens finishes. Colors: warm white, cool white, red, green, blue, orange, purple, pink, teal, gold, multicolor. Also available: RGB color-changing and ColorSplash multi-color blends (Arctic, Stardust, Champagne, Holly, Rainbow, Blue Taffy, Pink Taffy, Cotton Candy, Bahamas). Twinkle variants available.

C9 ProCore® String Sets — Stringer and bulbs bundled together; screw the bulbs into the stringer sockets. 25 lights, 25', 12" spacing. Faceted and smooth options. Full color range including ColorSplash blends.

C9 LED Filament Vintage Bulbs — Transparent shatterproof bulbs with a vintage filament look. Available in select colors.

C9 Use Cases

Rooflines and gutters: C9 is the industry standard for running lights along rooflines, gutters, and fascia — the larger bulb is clearly visible from the street.

Architectural outlines: Windows, doorways, peaks, dormers, and other architectural features where a defined light outline is the goal.

Note on outdoor tree wrapping: Outdoor tree wrapping is typically done with 5mm string lights — not C9. C9 is occasionally used around tree canopies for a modern visual effect, but this is not its primary use case.

C9 vs. C7 — Which Do I Need?

C9 (E17 intermediate base) is larger than C7 (E12 candelabra base). C9 is the standard for rooflines and large architectural outlines where maximum bulb visibility at a distance matters. C7 is well suited for indoor trees and smaller-scale architectural details.

Faceted vs. Smooth ProCore®

Faceted bulbs have a multi-faceted surface that catches and scatters light. Smooth bulbs have a clean, rounded finish for a uniform glow. Both available across the full color range.

How to Choose

C9 lights are the go-to choice for rooflines, gutters, fences, and architectural outlines where a large, bold bulb reads clearly at a distance. Choose between LED and incandescent based on your energy and longevity preferences — LED options run cooler and last longer. Measure your roofline footage before selecting a string length, and choose a color or multicolor combination that complements your display.

Frequently Asked Questions

Are C9 ProCore® bulbs dimmable? Steady-on C9 ProCore® bulbs are dimmable. Twinkle and RGB color-changing variants may not be compatible with dimmers.

What base does C9 use? Intermediate E17 base — standard for C9 stringers.

Do C9 sets come with bulbs included? No — ProCore® sets include the stringer and bulbs separately. Screw the bulbs into the stringer sockets.

What's the difference between C7 and C9? C9 uses an E17 base and is larger; C7 uses an E12 base and is smaller. C9 is the standard for rooflines and large-scale displays.

What's the Reindeer Proof™ Warranty? Our in-house warranty covering manufacturing defects and performance failures. Duration varies — see individual product pages.

Browse Related Collections

C9 LED Bulbs | C9 LED Light Sets | C7 Christmas Lights | C7/C9 Stringers | LED Christmas Light Bulbs