Manville Roof Vent

Any information on this roof vent? Is this sort of like a AAV vent for a roof to allow air to escape from under the roofing material? I looked online and have an idea what it’s use is but wanted to get some feed back on it from other inspectors.Do these really work?

Page 25 for technical details.

I have no first hand knowledge of actual performance in the field.

Interesting great find thanks David and Dominic… … Roy

FP-10 One Way Roof Vent On Sunshine Supply Co., Inc.

If you want to buy one

I agree, thanks guys!