Feature●Firecrest technology is neutral across the whole spectrum, including UV, visible and infra red●39mm diameter stackable filter reduces light by 3 F-stops●Firecrest multicoating technology makes the filter hydrophobic and scratch resistant●Manufactured in the UK using Schott Superwite glass, the finest optical glass availableDescription Firecrest ND 39mm Neutral density ND 0.9 (3 Stops) Filter for photo, video, broadcast and cinema production.