The Meijiu NB240 LM281B Quantum Board is a 240 W dimmable LED grow light built around a single full‑spectrum quantum board using Samsung LM281B diodes with added 660 nm deep red. It is specified for a flowering footprint of 2.5 x 2.5 or 3 x 3 feet, with a 4 x 4 foot veg area, and a system efficacy up to 2.65 μmol/J. At recommended mounting heights, the fixture delivers a listed 1177 PPFD and operates on 90–277 VAC. The passive‑cooled board measures 24.88 x 9.84 inches and is powered by an Inventronics driver with 0–10 V dimming and RJ control compatibility; note the dimmer does not turn the lamp fully off. Rated lifetime is 50,000 hours and it is positioned to replace a 600 W HID.
