The LED filament, also known as chip-on-glass, is made up of many series-connected LEDs on a transparent substrate (COG). These translucent substrates are constructed from sapphire or glass. The emitted light may disperse evenly and uniformly without any obstruction thanks to this transparency. The employment of more LED emitters with lower driving currents results in a potential increase in efficiency, which is a benefit of the filament design. A significant advantage of the concept is how easily arrays of filaments may provide nearly complete "global" (360°) illumination, however two zones that emit less light appear diagonal to the substrate.