Hoya HD3 lens filters claim to be 4x stronger than optical glass: Digital Photography Review
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Hoya 40.5MM NXT Plus UV Filter A-NXTPL405UV - Best Buy
HOYA UV Filter DMC LPF Pro 1D 37_40.5_43_46_49_52_55_58_62_67_72_77_82mm Digital for Nikon Canon Sony Fuji camera accessories - AliExpress Consumer Electronics