Under normal circumstances LED fluorescent light-emitting angle of 120 to 140 degrees, LED fluorescent light is directional, unlike fluorescent lamps that light-emitting non-directional 360-degree, usually mounted on the ceiling. Downward irradiation.
When people buy the installation of LED hand, often have a confusion that is normal to install LED bracket, LED illumination surface (transmission surface) is facing the bracket instead it should irradiated areas. This causes the LED will not achieve its proper role, lighting functions greatly reduced.
This is because when the production assembly workshop LED, and not well controlled illumination angle (especially PC + AL lamp only 120 degrees against the light angle) mounting angle to conform with the lamp pins. The glass led tube do not have this issue, because the beam angle of it is 330 degree.
But if some market need the PC+Al one,the rotatable cap can be a good solution to this problem. When after a LED has a pivoting head, you only need to properly install the lamp to the bracket, as you need to adjust the angle of illumination.