English to Chinese Tech/Engineering Engineering (general) glasses (sunglasses)

what 's the correct chinese term for the EN ISO 12312-1 for "filter categories" ?
滤镜类别 or 滤光等级 ?

The number indicates the filter category as defined by the standard EN ISO 12312-1.
Very dark special purpose sunglasses (filter category 4) .....

As shown overleaf a new development in the new standard is the use of symbols that are allowed for the various filter categories as an alternative or addition to wording. Symbols are useful in a European context in view of the plethora of languages extant in Europe. With regard to marking the new standard in no way alters the requirement for CE marking of Sunglasses for sale in the European Union.