Elco Lighting has been building recessed downlights out of Vernon, California, since the 1990s, and its catalog now spans thousands of SKUs across residential and commercial recessed lighting. Rock Lighting stocks the Elco Lighting line in full, and the most common question from contractors and designers is simple: which Elco system fits the job, Koto, Oak, or Pex?
The short answer is that Koto and Oak are the two LED module platforms, and Pex is a trim family that mounts to the Koto module. This guide breaks down what each one actually is, where it fits, and the specs that matter when you are specifying one over another. Browse the full line on our Elco Lighting collection.
Koto: the 2-inch aperture system for high-end residential and light commercial
The Koto system is built around a 2-inch aperture LED module with an integral driver. The same module locks into a wide range of twist-on trims (2", 3", 4", and 6") using a tool-free twist connection, so one module platform covers reflector, adjustable, pinhole, slot-aperture, and wall-wash trim styles without changing the light engine.
Per Elco's Koto System catalog:
- Input power: 10W to 12.5W depending on module (ELK07/ELK09/ELK11 series)
- Lumen output: 770 lm to 1,260 lm across the standard module line (up to 1,690 lm across the full Koto trim family per Elco's styles chart)
- Color temperature: 2700K to 4000K, plus a Sunset (dim-to-warm, 3000K to 1800K) option
- CRI: 95+
- Beam angle: 38° standard, with field-changeable 28° and 60° lenses (18° available as an accessory)
- Rated: IC, wet location with wet trims, Title 24 JA8-2016 registered, ENERGY STAR certified
- Life span: 50,000 hours L70, 5-year warranty
The Koto Focus module adds a twist-adjustable beam from 18° to 50° without swapping lenses, useful when a single fixture needs to serve both a wash and an accent role.
Oak: Elco's 1-inch miniature LED system
The Oak system is Elco's smallest recessed platform, built around a 1-inch aperture. It is designed for shallow ceilings and tight retrofit or new-construction applications where a full-size can will not fit, and it runs on 12V AC rather than line voltage, so it requires a companion transformer (a single E1LDRV60, LET-60 series, or ETR12 transformer can daisy-chain up to 6 Oak fixtures).
Per Elco's Oak System catalog:
- Input power: 6W to 6.4W depending on style
- Lumen output: 450 lm to 700 lm depending on color temperature and fixture style
- Color temperature: 2700K to 4000K, plus Sunset
- CRI: 93+
- Beam angle: 38° standard, with 28° and 50° options
- Rated: IC airtight, wet location (round/square downlights) or damp location (adjustables), Title 24 JA8-2016-E, UL Listed, ENERGY STAR Listed
- Life span: 50,000 hours L70, 5-year warranty
- Finishes: white, black, bronze, haze (availability varies by style)
Oak ships in four fixture styles: fixed round/square downlights (E1L02/E1L12), round/square adjustable pull-downs with 30° of gimbal movement (E1L32/E1L22), and a trimless downlight (E1L61) that hides the trim ring entirely, plus dedicated new-construction housings (E1LF1 for downlights, E1LF2 for adjustables and trimless). See our companion deep-dive on the Oak system's exact SKUs and finish options.
Pex: the trim family, not a separate module
Pex is not a third LED engine. It is one of Elco's twist-on trim lines that mounts to the Koto LED module, in this case a deep-reflector and adjustable-reflector trim series available in 3" and 4" round and square formats (for example, ELK3618W and ELK4118W). If you already understand Koto's module specs above, Pex trims share the same electrical and photometric performance; the difference is purely the reflector geometry and finish.
How to choose
For most new-construction residential and light-commercial recessed lighting, Koto is the workhorse: 2" aperture, line-voltage driver, and the widest trim selection. Reach for Oak when ceiling depth, a tight remodel cavity, or a very small aperture is the deciding factor, and budget for the low-voltage transformer that Oak requires. Pex, and Elco's other Koto-compatible trim lines, let you dial in the exact reflector look (deep, adjustable, wall-wash) once you have settled on the Koto module.
Rock Lighting stocks the full Elco Lighting recessed line, including the Residential Downlights collection. If you are pricing a project, our team can confirm current stock and lead times, or put together a full package with sensors, controls, and dimmers.
Frequently asked questions
Is Elco's Koto or Oak system better for a standard 6-inch can retrofit?
Koto is the more common fit for standard new-construction and retrofit housings because it runs on line voltage and covers 2", 3", 4", and 6" trims from one module platform. Oak is a 1-inch system built for shallow ceilings or very tight apertures, not a direct swap for a standard 6-inch can.
Does the Oak system need a separate transformer?
Yes. Oak runs on 12V AC, so it requires a compatible transformer such as the E1LDRV60, LET-60 series, or ETR12, each of which can daisy-chain up to 6 Oak fixtures.
What CRI do Elco's Koto and Oak modules deliver?
The Koto LED module is rated 95+ CRI. The Oak system is rated 93+ CRI. Both exceed the 90 CRI threshold commonly specified for residential and hospitality projects.
Are Elco Koto and Oak fixtures Title 24 compliant?
Per Elco's catalogs, the Koto module is Title 24 JA8-2016 registered and the Oak system is Title 24 JA8-2016-E compliant. Confirm the specific SKU and finish against the current JA8 appliance directory for your project's code cycle before final spec.
What is a Pex trim, exactly?
Pex is a twist-on reflector trim line for the Koto LED module, available in deep and adjustable-reflector styles in round and square formats. It is not a separate light engine; it shares the Koto module's electrical and photometric specs.
Does Rock Lighting stock Elco Lighting products?
Yes. Rock Lighting carries the Elco Lighting catalog, including the Koto, Oak, and Pex trim lines. Browse the Elco Lighting collection or contact us for stock and lead-time confirmation on a specific SKU.
Ready to spec a project? Register for a contractor account, request a quote, or contact us and we will help you match the right Elco system to your ceiling and application.
Related guides
This guide is general information. Specifications (lumens, wattage, CRI, ratings) are sourced from ELCO Lighting's Koto and Oak system catalogs and may change without notice; confirm current figures against the manufacturer spec sheet or your quote before final purchase.