In addition, a lens hood is always cut to the smallest focal length. Therefore, it is already time to assert complete nonsense, the same lens hood dignity for lenses with focal lengths from 18mm to minimum 75mm functioning effectively. By comparison, just look at the huge disparity of the original lens hoods Canon View - Canon knows why each lens needs a completely different panel.
Who wants to dazzle others and just want to have a 'more professional' appearance may be something to buy (but should then turn off the auto focus, because otherwise it will be embarrassing if the tulip turns). Those who want a functional lens hood should leave it alone.
BACKGROUND: The tulip shape is intended to overshadow the rectangular cutout of the sensor optimally - thus here the aperture in the corners is less than at the edges. Rotate the bezel does not fit the course.