You know .... in all fairness - I never really noticed the model number of the covers I tried. They each came in a white box with EV logo's all over it, and I never read themodel number. My dealer guy just sent them as per what I asked for. The sx300 and the sxA100 have the same size outer shell, but those darn fins stick out past the side of the unit. That's where the differance lies. It was a real chore not to rip them in the first trial use ! Beware !