Fire crest Neutral Density is a revolutionary new type of ND filter from Format-Hitech. Rather than dyed resin, Fire crest is a carbon metallic coating used to create hyper neutral NDs. These circular ND filters are made from Schott Super white glass and feature stackable 5.5mm Super Slim rings. Fire crest Neutral Density filters are hydrophobic, anti-reflective and extremely flare resistant, which increases contrast and visual acuity in challenging lighting conditions. This 77mm Fire crest Neutral Density filter reduces light by 5 stops