This rotating lens hood is designed for digital cameras with either built-in or interchangeable zoom lenses. The hood protects against stray light reflection hitting the surface of the lens.
Function
This item can inhibit stray light into the lens and eliminate the haze, improve the clarity of the imaging and colour reproduction.
Prevent glare by stopping light from coming into the lens at side angles 
Improves contrast and image quality 
Protects lens from scratches and impacts 
You can use lens cap and filter with the hood on a lens 
Protects lens from dirt 
Increase transparency