Here is the specs I got from another site that sells the BF1217

Fuel Filter, 7-11/32x3-11/16x7-11/32 In

BALDWIN FILTERS | Zoro #: G1044766 | Mfr #: BF1217
Details:
Includes: Drain, I. Gasket
Description/Special Features: Fuel/Water Separator Spin-on with Drain
Micron Rating: 40
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While it does say Micron Rating: 40 it does not say if it is part of a nominal or a Beta rating. Is that a typo?

You might go to the Baldwin Filter site and send a message to the tech department and ask them what the Filter efficiency is. Within a week they will answer.

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84 300D, 82 Volvo 244Gl Diesel