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Looks like the ADBV is a thin piece of (spring loaded?) metal, not rubber....
Some Purflux spin on use a spring loaded metal back nitrile adbv. Not sure that the case here, possible I'd think. Of something similar.
I agree the Cat filter appears well made. Two pieces of information not included here, the everyday cost for one and an efficiency spec. I realize the latter not important to some, however if appearance is the sole basis other filters should be judged the same imo. Also if the topic filter fetches a premium price, I'd want an ISO efficiency spec to go with it. My .02