Bobo, that is correct. You can see how it installs here, it is very easy: http://www.phantomfilters.bigcartel.com/installation When unscrewing the UV-filter I usually just lightly shake or 'tab' the UV filter into my other hand to let the www.PhantomFilters.com ND-filter fall out. Careful that the little rubber seal from the UV-filter might come out too. Just put it back before putting back the UV-filter.