ZOMEI Gradient Neutral Density Cokin P Series Graduated ND2 ND4 ND8 ND16 Filter Set for Canon Digital SLR Camera Lens We will send this parcel by epacket, it will take about 5-15 days to reach USA. The filter is placed in front of the camera lens to modulate the quantity of light that reach the sensor in order to modify colors, contrast, saturation, shutter-speed, depth-of-field and such parameters. This is a Complete ND set includes: Graduated ND2 ,ND4, ND8 filters. Full ND2, ND4, ND8 filters, one square filter holder, one square lens hood, nine sizes adapter rings: 49mm 52mm 55mm 58mm 62mm 67mm 72mm 77mm and 82mm to fit most lenses. This kit also includes a six pocket wallet style case to hold the ND filters. ND filters reduce the amount of light reaching the film without affecting the color. These filters are compatable with the Cokin P series.