FOHSE’s 121 is a high‑intensity LED top-light engineered as a direct 1:1 replacement for legacy HPS fixtures. The 850 W fixture delivers 2,185 μmol/s PPF with a photosynthetic efficacy of 2.50–2.65 μmol/J, aided by a high‑performance lensing system for deeper canopy penetration. It carries an IP66 ingress‑protection rating and supports both 120–277 Vac and 277–480 Vac inputs. The chassis measures 63.5 × 40.6 × 11.9 cm and weighs about 12.0 kg. FOHSE builds the 121 around LEDstar 5050 diodes and positions it for robust operation in washdown grow rooms. FOHSE marketing notes “options up to” 2,810 μmol/s and 2.81 μmol/J, while the published tech sheet specifies the 850 W configuration above. Typical rated life is around 50,000 hours, minimizing relamping versus HPS.