360 µmol/s of flowering-weighted light where your toplight can't reach.
The Flexstar Under Canopy 120W R8W is a purpose-built supplemental LED strip delivering 360 µmol/s at 3.0 µmol/J efficacy — a flowering-focused spectrum engineered to activate lower bud sites, even canopy development, and total usable harvest in commercial cannabis and hemp rooms.
The Flexstar Under Canopy 120W R8W is a slim-profile LED bar fixture built specifically to address one of the most persistent yield problems in dense canopy cultivation: the lower bud zone that your primary toplight simply cannot penetrate. At 45.6 inches long and under 3 inches wide, the fixture sits between canopy layers without crowding plant sites or interfering with airflow.
The R8W variant carries a red-channel-weighted diode configuration that skews its spectrum toward flowering-stage wavelengths — supporting bud density and branch strength in the lower canopy layers that are most often underdeveloped or removed entirely in a lollipopping protocol. At 3.0 µmol/J, the R8W is the higher-efficiency option in the 120W Under Canopy lineup (compared to the R5W's 2.8 µmol/J), making it the preferred choice for large-scale builds where cumulative energy costs on supplemental fixtures add up quickly.
This fixture is designed for licensed cannabis and hemp cultivation operators running commercial indoor rooms — particularly those using multi-tier vertical racks, dense single-tier canopies, or any configuration where the primary overhead fixture leaves significant light deficits below the top 12–18 inches of plant canopy. It's also a practical choice for operators who are lollipopping aggressively to protect harvest uniformity but want to recover those lower sites instead.
Multi-site operators and master growers who are spec'ing a full room build — rather than adding a handful of units reactively — will get the most out of the daisy-chain architecture: up to 17 fixtures per run means one power connection can feed a full rack row or a substantial bench run, keeping conduit and outlet count manageable at scale. The 120V–277V input voltage range covers both standard commercial panels and higher-voltage three-phase infrastructure without requiring a separate driver or adapter.
IP66 ingress protection is the spec that matters most in a high-humidity flowering room. The Flexstar UCL's IP66 rating means the fixture is sealed against high-pressure water jets — it survives daily foliar spray, overhead irrigation blowback, and washdown without damage to the diodes or driver. Passive cooling (no fans, no moving parts) eliminates failure points and keeps maintenance to cleaning rather than component replacement.
Dimming is handled via 0–10V signal with a 40%–100% range (plus an OFF state), so the fixture integrates cleanly with any environmental controller or lighting controller that outputs a standard 0–10V dimming signal. The 120° beam angle distributes light broadly across the lower canopy rather than creating a concentrated hotspot directly beneath the bar — critical when the target is even canopy uniformity rather than a single high-PPFD zone. Rated lifetime is L90 greater than 50,000 hours. The fixture carries ETL, DLC, and CE certifications; DLC listing makes it eligible for utility rebate programs in qualifying U.S. states.
In a single-tier room, the UCL mounts horizontally inside the canopy — typically along trellis or below the canopy line — to deliver direct light to mid- and lower-canopy bud sites without raising ambient room temperature the way adding another toplight would. In a vertical rack configuration, one bar per shelf tier is a common starting point, supplementing the primary overhead fixture on each level and improving uniformity across the entire column.
The daisy-chain snap-together design means installation is fast: fixtures connect directly or with 3-foot extension cords to create spacing between units. Mounting works in both under-canopy (downward-facing on a shelf) and above-canopy (upward-facing or angled) orientations depending on your canopy architecture. For large runs, Flexstar also offers the X2 Zeus controller for coordinated dimming control across multiple daisy chains. Contact HSC to spec the right unit count and run layout for your canopy footprint.
| Model | Under Canopy 120W R8W |
| SKU | 307117 |
| Input Power | 120W |
| PPF | 360 µmol/s |
| Efficacy | 3.0 µmol/J |
| Input Voltage | 120V–277V |
| Fixture Dimensions | 45.6" L × 2.9" W × 3.3" H (115.7 × 7.5 × 8.5 cm) |
| Weight | 5.73 lb (2.6 kg) |
| Dimming | 0–10V, 40%–100% / OFF |
| Daisy-Chain Capacity | Up to 17 units per run |
| Beam Angle | 120° |
| Cooling | Passive |
Both are 120W fixtures with the same physical form factor. The R5W outputs 340 µmol/s at 2.8 µmol/J. The R8W — this listing — outputs 360 µmol/s at 3.0 µmol/J, with a higher concentration of red-channel diodes. The R8W is the better choice for flowering-stage supplemental lighting where you want maximum photon delivery and efficiency at the diode level. The R5W is an option for veg supplementation or where a slightly softer spectrum balance is preferred.
That depends on your canopy width, plant density, and how much of your lower bud zone is currently receiving adequate PPFD from your primary toplight. For a standard 4-foot-wide bench or shelf, one 45.6-inch bar per tier is a common starting point. For wider benches or particularly dense canopies, a second bar per tier may be warranted. Contact HSC with your room dimensions and we can help spec a layout.
No. The driver is integrated into the fixture. It accepts 120V–277V AC input directly — no external ballast or adapter required. The 0–10V dimming signal wire connects to your environmental or lighting controller.
IP66 is rated for protection against high-pressure water jets from any direction — this is the appropriate rating for commercial flowering environments with overhead irrigation, foliar spray, and routine washdown. The passive cooling design (no fans or vents) removes the most common IP compromise point found in active-cooled fixtures.
The Flexstar Under Canopy 120W is DLC-listed, which is the primary qualification standard for most commercial utility incentive programs in the U.S. that cover horticultural lighting. Rebate availability and amount vary by state and utility provider. HSC can supply the DLC listing documentation needed for most rebate applications.
Get operator-direct pricing and availability. We supply licensed commercial cultivators nationwide.
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