This I-Beam Fluorescent High Bay fixture has a more focused light output with 4, 6 lamps options for different situations in warehouse, retail, or other big spaces. For easier maintenance, the ballast is covered by a reflector which is locked with tool-less twist locks. The shape body frame is constructed with cold roll steel and powder coating for extended fixture life. Rotary-lock-amp-holders come as standard and reflector is made from aluminum with 95% reflective finish to maximum efficiency. If desired, this product can be ordered upon request with the sensors to minimize unused energy.