This hood is collapsible and can be retracted or extended to fit various focal lengths. The rubber itself is fairly thin, which is good because it's very lightweight but not so good because a small bump can extend or retract it by mistake. This is fairly easy to notice as soon as you look through your viewfinder but can be annoying at times. The hood screws on so, once it's on, it's on, which I prefer to the lens manufacturer's hoods, most of which are easily knocked off at the most inconvenient times. All in all it's a good hood and, if you shoot sports like basketball, you have to have a rubber hood on your lens.