Zomei&reg; Nd4 Filter with Standard Ring Adaper for Gopro Lens 3 3+ 4 Accessory Aluminum material-lightweight, Black Anodise-Durable, CNC cutting-Precision,educes Blown out Highlights while filming in bright conditions Standard Adapter, Protecting Cap for Gopro 3 3+ 4 and Slow Down Cameras Shutter Speed By 2 Stops,Knurling Edge Frame. These filters are equipped with a straight knurling edge for non-slip, easy attachement and removal