Warehouse-Lighting.com’s 70W 120-277V electronic
HID ballasts, metal halide, with ballasts are UL listed and include safety
features such as short-circuit protection and open-circuit protection. Made by
Espen, these ballasts have a power factor of 0.95 and a minimum start
temperature of -20 degrees Fahrenheit. They come with a three-year warranty and
are available with bulk discounts.