hi sabar, i dont have one myself but i think you mean 75-300 . also they are not actually made for any individual lens but made for the type of camera (canon , nikon) so any lens should fit. i think they would be a good buy for many reasons and are not so expensive compared to buying a sigma 170-500mm for example, the only thing i’ve read in reviews is that you loose some image quallity (noise) but i’m sure it wouldn’t be to much to put me off buying one. hope this is of some help . eamonn