Christmas light stringers are bare sockets on heavy-duty wire with bulbs sold separately. C7 stringers use E12 sockets for smaller C7 bulbs; C9 stringers use E17 sockets for larger C9 bulbs. Choose pre-sized stringers from 10 to 119 feet, best for a ready-to-hang length, or bulk spools in 500 and 1,000 feet that can be custom cut.
What Is a Christmas Light Stringer?
A Christmas light stringer is a length of heavy-duty wire with bare sockets pre-installed at fixed spacings. The bulbs are sold separately, so you pick the bulb and the color, and swap them later without replacing the whole string. Stringers and spools are rated for indoor and outdoor use, so one string works anywhere you install it. Professional sockets feature weep holes for trouble-free performance through rain and snow. Unlike prelamped sets, which come with bulbs already wired in, building from a stringer gives you more control over the finished display.
C7 vs C9: Choosing the Right Stringer Size
Sockets come in two sizes: E12 (candelabra) for C7 bulbs, and E17 (intermediate) for C9 bulbs, globe shapes, and a variety of party bulbs, so you match the string to the bulb size your display calls for. The two socket sizes are not interchangeable. Both sizes come as pre-sized stringers from 10 to 119 feet and bulk spools in 500 and 1,000 feet, covering anything from a single porch to a commercial property.
C9 is the larger bulb, 3" tall, bold and visible from the street — the classic choice for rooflines and large displays. C7 is the smaller bulb, 2" tall, ideal for railings, porches, trees, and closer-viewing displays or smaller spaces — equally at home on a roofline if you prefer the look.
E17 sockets also accept C9 and many G-globe bulbs, so the same string can be used at Christmas and again during patio season.
Stringers and Spools
A stringer is pre-sized to length with the plugs already attached, available from 10 to 119 feet and ready to hang. A polarized fused plug on every stringer guards against electrical surges, protecting everything connected to it, and a male and female plug on every pre-sized stringer can connect one string to the next, so a single outlet can carry the whole line of light. Pre-sized stringers carry a fused plug, capping the load at 960 watts, which is more than 1,000 LED bulbs.
Spools ship as continuous wire with no plugs, so you cut to the exact length your project needs. Bulk spools come in 500 and 1,000 feet, enough wire for large residential and commercial projects from a single spool. Cut between sockets and cap each end with a zip plug or appropriate sealant matched to the wire type (SPT1 or SPT2).
Wire Color, Spacing, and Wire Type
Wire color — available in green, white, black and brown, so the wire matches the surface it mounts on and blends in during daylight: green with greenery, white with white gutters, black with dark fascia, brown with natural wood.
Socket spacing — choose from 6 to 24 inches, so you control how full the line of light looks: tight for a dense glow up close, or wider to cover a long roofline and stretch your budget. 12-inch spacing is the most common choice for residential displays, and 6-inch creates a denser look for trees and close-up displays. C7 comes in 6, 12, 15, and 18-inch spacing; C9 adds a 24-inch option.
Wire type — strings come in SPT1 or SPT2 wire, with SPT2 carrying thicker insulation for harsher weather and SPT1 handling most Christmas light displays. Heavy-duty 18-gauge commercial-grade wire reduces voltage drop so you can run longer light strings from a single power source. Built with UL Recognized Components for safety and peace of mind.
Pro Tip:
Pro Tip: Pick your stringer first, then your bulbs. The stringer locks in your socket size (C7 or C9), socket spacing, wire color, length, and wire type (SPT1 or SPT2). Once those are set, choose bulbs to match — any C7 bulb fits any C7 stringer, and any C9 bulb fits any C9 stringer, regardless of bulb style or technology. That flexibility is the whole point of building from a stringer. Later, swap in new colors or upgrade from incandescent to LED without replacing the wire.
Frequently Asked Questions:
Do Christmas light stringers come with bulbs? No. Stringers and spools are bare sockets with bulbs sold separately, so you pick the bulb and the color, and swap them later without replacing the whole string. This is different from prelamped sets, which include bulbs already wired in.
Should I buy a light stringer or a spool? Choose pre-sized stringers for a ready-to-hang length or bulk spools that can be custom cut so the string fits the project. Pre-sized stringers come in lengths from 10 to 119 feet with the plugs already attached. Bulk spools come in 500 and 1,000 feet, enough wire for large residential and commercial projects from a single spool.
What socket spacing should I choose for Christmas light stringers? Christmas light stringers are available in spacing options from 6 to 24 inches, so you control how full the line of light looks. 12-inch spacing is the most common choice for residential displays, and 6-inch creates a denser look for trees and close-up displays. C7 comes in 6, 12, 15, and 18-inch spacing; C9 adds a 24-inch option.
What is the difference between SPT1 and SPT2 light strings? Strings come in SPT1 or SPT2 wire, with SPT2 carrying thicker insulation for harsher weather and SPT1 handling most Christmas light displays. Both use heavy-duty 18-gauge commercial-grade wire.
Can I cut a Christmas light spool to length? Spools ship as continuous wire with no plugs, so you cut to the exact length your project needs: cut between sockets and cap each end with a zip plug matched to the wire type (SPT1 or SPT2) or appropriate sealant. Pre-sized stringers arrive with the plugs already attached and ready to hang, so a defined length rarely needs cutting.
What color wire is best for Christmas light stringers? Christmas light stringers are available in green, white, black and brown, so the wire matches the surface it mounts on and blends in during daylight: green with greenery, white with white gutters, black with dark fascia, brown with natural wood.
