5 Years Warranty Led Ufo High Bay 60W-300W For Led Gym Lighting,factory Lighting

- Aug 10, 2017-

Brightness is used to indicate the surface of the object luminous (or reflective) the strength of the physical volume, the luminous surface of the object in the direction of light intensity and the luminous surface in the direction of the projection area perpendicular to the ratio, called the surface brightness of the luminous surface, the unit is a $literal per square metre.