Optical system: Self-flanged semi-specular, matte-diffuse or specular lower reflector. Patented Bounding Ray™ optical design (U.S. Patent No. 5,800,050). 45° cutoff to source and source image. Top-down flash characteristic. Mechanical system: 16-gauge galvanized steel construction; maximum 1-1/2” ceiling thickness. Telescopic mounting bars maximum of 32” and minimum of 15”, preinstalled, 4” vertical adjustment. Toolless adjustments post installation. Junction box capacity: 8 (4 in, 4 out ) 12AWG rated for 90°C. Light engine and driver accessible through aperture. Electrical system: Fully serviceable and upgradeable lensed LED light engine. 70% lumen maintenance at 60,000 hours based on IESNA LM-79-2008. 120-277VAC, 50/60hz power supply with 0-10V dimming (10-100%); rated for 50,000-hour life. Overload and short circuit protected. LEDs tested under LM80. Listings: Fixtures are CSA certified to meet US and Canadian standards; wet location, covered ceiling.