Firecrest 46mm Superslim stackable multicoated UV 370 Filter 39mm Firecrest UV 370mm multicoated filter in stackable 5.5mm ring 370nM is our mid level UV, suitable for professional application and everyday use Built in the UK using Schott Superwite glass for highest image fidelity Firecrest multicoating is anti reflective, anti scratch and hydrophobic for shooting in most challenging conditions Provides essential lens protection whilst improving image quality by reducing UV pollution