SPT-1 Lamp Cord Extension Wire - Bulk Spool

Why the SPT-1 lamp cord extension wire earns its place on the contractor truck

Build custom extension cords, jumpers, and lead lines for any Christmas light install with our bulk SPT-1 lamp cord (zip cord). Cut to the exact length you need, crimp on plugs, and skip the mess of mismatched store-bought extension cords forever. Available in three spool sizes and four wire colors so you can match every install scenario — from residential rooflines to commercial properties to landscape and tree displays.

Why Pros Build with Bulk SPT-1 Zip Cord

Stop overpaying for pre-made extension cords. Buying bulk zip cord and crimping your own plugs costs a fraction of buying pre-assembled extension cords — and the savings add up fast across a season of installs.

Get the exact length, every time. No more 25-foot extension cord coiled on the ground because you only needed 14 feet. Cut to length, crimp, done.

Build cleaner installs. Custom-length jumpers between roofline runs, ridge-to-soffit drops, and tree-to-power leads all look better when the wire matches the actual distance instead of dangling excess.

Match the wire to the surface. With four color options, you can hide the wire against any background — a small detail that separates a pro install from a DIY job. It's why thousands of installers in our 40,000+ contractor community keep multiple colors on the truck.

Spool Length Options

Choose the spool size that matches your install volume:

• 250 ft spool — Right-sized for smaller crews, single-property jobs, or keeping a backup color on the truck without overcommitting.
• 500 ft spool — The most popular size for active residential installers. Enough wire for a full season of jumpers and custom extensions without taking up too much truck space.
• 1000 ft spool — Best per-foot value. The right call for high-volume installers, commercial accounts, and crews running multiple jobs per day.

Wire Color Options

All four colors are functionally identical — choose based on where the wire will be visible:

• Green — Disappears into landscaping, trees, shrubs, wreaths, and garland. The default for any install where the wire will run through foliage.
• White — Blends into white fascia, soffit, gutters, and trim on light-colored homes.
• Black — The cleanest option against dark roofing, dark siding, asphalt, and shadowed runs. Also the standard choice for stage and event lighting.
• Brown — Hides against brick, stone, wood siding, cedar shake, and natural surfaces. Often overlooked, but the right call on a lot of higher-end residential jobs.

Specs

• 18 AWG, 2-conductor SPT-1 zip cord
• Rated 8 amps / 960 watts at 120V
• UL-listed for indoor and outdoor use
• Weather-resistant insulation — handles UV, freezing temps, ice, and seasonal install/teardown cycles
• Splits cleanly for plug installation — the standard zip cord design separates easily for crimping male and female SPT-1 plugs

What Pros Use This For

• Custom-length extension cords cut to exact distances
• Jumper wires between roofline runs, peaks, and ridges
• Power leads from outlets to the start of a stringer
• Drop wires from soffits to ground-level displays
• Extending C7 or C9 stringers without bunching excess wire
• Stage, event, and temporary lighting setups

What You'll Need to Complete the Install

To turn this spool into finished extension cords or jumpers, you'll also need:

• SPT-1 male plugs (vampire or screw-on)
• SPT-1 female plugs (vampire or screw-on)
• An SPT-1 crimping tool (for vampire plugs)

Verified specifications

Every value below is pulled from the printed bag label / spec sheet. No marketing inflation.

When to spec SPT-1 over SPT-2

What this wire works with

Plugs

SPT-1 male + female slide-on plugs ONLY. Never SPT-2 plugs on SPT-1 wire. Shop plugs

Loads

120V Christmas light circuits up to 7 A: C9, C7, mini-light strings, indoor garland.

Install routing

Indoor or covered outdoor only — soffit, attic, basement, covered porch.

Will NOT work with

Direct outdoor exposure in cold-climate (SPT-2 required), 240V circuits, direct burial.

SPT-1 vs SPT-2 lamp cord extension wire

How to build an SPT-1 extension cord

1. Measure the run. Add 4-6 ft for slack. Cut wire to length from the spool.
2. Don't strip the jacket. SPT-1 slide-on plugs use IDC teeth that bite through the jacket when the plug cover snaps. Stripping defeats the connection mechanism.
3. Slide on plugs and snap covers. Male plug on supply end, female (knockout-tab capped) on line end. Snap until you hear the click.
4. Test with an outlet tester. Confirm hot/neutral polarity before live deployment.
5. Route along sheltered paths. Indoor: tuck behind baseboards or run through cord covers. Covered outdoor: route along soffit and stake to landscape.

Build quality + materials

• UV-stabilized PVC jacket — survives indoor and sheltered-outdoor environments across multiple seasons.
• 18 AWG copper conductor — meets UL standard for 120V Christmas light loads up to 7 amps.
• Slide-on plug compatible — works with all standard SPT-1 male + female plug variants.

Warranty

1-year manufacturer warranty on bulk SPT-1 wire from Christmas Lights HQ. Covers manufacturing defects and insulation failure in the first season. Not covered: cuts from sharp tools, animal damage, cross-matched plugs, outdoor cold-climate exposure beyond the sheltered rating.

Full warranty terms →

Questions contractors actually ask

Customer reviews

Build the complete SPT-1 line

Orders placed before 2 PM ET ship the same day. Free shipping on orders over $349. Most orders arrive in 2-5 business days via UPS or FedEx Ground.