WonderPana 186mm Slim Neutral Density 1000 10-Stop Filter - Slim ND1000 Filter works w/ WonderPana 186 Systems Premium Grade Optical Glass Filter; High Quality, Single Threaded, Slim ND1000 Filter; Premium Grade Anodized Aluminum Ring, 186mm x 1mm Standard Filter Thread Enables slow shutter speeds to be used, allowing film to record movement in subjects such as waterfalls, clouds, or cars Decrease depth of field by allowing wider apertures to be used, in turn helping to separate subjects from their background Other 186mm Filters Include: MC-UV, CPL, MC-CPL, Slim ND4/8/16/32 24-Month Manufacturer Warranty