It is made of durable plastic and can be attached firmly and securely to the lens. As you can you turn even the lens + lens hood sun does not really need more space in the camera bag than before.
The quality, with an attached sun lens hood, made photos improved logically through the intercepted scattered light. To vignetting by the lens hood, it is not.
Strong buy recommendation if you like me as a sun lens hood for Canon EF 75-300mm needed. (Whether the sun hood in perfect harmony with the EF-S 55-250 mm I can not say, of course)