These body seals are used as replacement on the Edwards EMF10 Oil Mist Filter, which is suitable for all Edwards Rotary vane pumps up to E2M18. That filter is very efficient at 99.999% DOP test and is also azide proof. The white bottom half of the body is semi-transparent, allowing the oil level to be monitored. Replacement oil elements and odor elements are available on this website. For complete specifications download instruction manual (see below avaliable below). These replacement seals have Edwards Part Number A271-59-535 (A27159535).