pre-filter with paper frame applys to filter dust through air filter program .We ... 19001-2000... 1. We can produce pre-filter with paper frame, which has different efficiency from G2-G5, which applys ... Canada, USA, Australia, Italy, Hungary, Thailand , Vietnam, Yemen, Venezuela, Iran, Bangladesh, Georgia, HK etc.Reason 8Delivery can be in as ... back guarantee in 60 days pre-filter with paper frame