Specifications include, but are not limited to: CONSTRUCTION: Body is 20-gauge die-formed steel with an 18-gauge die-formed internal joiner system. Plugtogether wiring standard. All components are hard-tooled to tolerances of +/- 0.010". ENDCAPS: The Flat Endcap (FE) is standard and made of 20-gauge die-formed steel adding 0.1" at each end. The optional Curved Endcap (CE) is an aluminum die-cast endcap with a 0.100" reveal adding 5.0" at each end. UPLIGHT TOP OPTICS: The 2E optical system is open, standard. Optional Frosted Top Optic (FTO) and Clear Top Optic (CTO), available. SHIELDING OPTIONS: DCO Diffuse Center Optic, 73% transmissive, 99% diffusion. WCB White Cross Baffle, 87 cell baffles spaced 0.5" apart and finished with 96% reflective white paint. PLV Parabolic Louver, Semi-specular louvers with straight edges, spaced approximately 1.2" apart. LIGHT OUTPUT: Four lumen packages available, Standard Output (S), Boosted Standard Output (B), High Output (H), and Very High Output (V). A separate chart summarizes lumen distribution and wattage. Light engines are replaceable. LUMEN MAINTENANCE: 90% of initial light output (L90) at 100,000+ hours; 70% of initial light output (L70) at 200,000+ hours. DRIVER: Replaceable 120V/277V Constant Current Reduction dimming driver standard. Can be wired dimming or non-dimming. 0-10V dimming controls with a range of 10%-100%. Dimming to 1% available; consult factory. Driver is fully accessible from below the ceiling. Power Factor: ≥0.9. Total Harmonic Distortion (THD) <20%. Expected driver lifetime: 100,000 hours. LUTRON DRIVER OPTIONS: Lut3W-3-wire, LutESEcoSystem, Lut2W-2-wire. ELECTRICAL: Optional emergency to generator/inverter wiring, internal generator transfer switch, nightlight wiring, step-dimming driver, backup battery. Optional Chicago Plenum available. A factory-choice low-profile backup battery is available (8' minimum fixture length). Backup batteries deliver 1600 lumens. A 4' section will be illuminated in emergency mode.