The ND3.0 1000x filter extends the exposure time by factor 1000, which corresponds, to 10 f-stops. Example: an exposure time of 1/1000s can change to 1s using the ND3.0 1000x neutral density filter. As an effect of longer exposure time, you can for example "eliminate" people moving on squares or landscapes. Available in filter sizes 37mm, 40.5mm, 43mm, 46mm, 49mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm and 82mm.