Product review (2 stars): Cool design but super poor in efficiency
I've been solely involved with dryer venting for over 15 years.  When I ran a Back Pressure test on these "wiffle ball" style vents I found them very high in the delta or additional back pressure they provided.  The concept is great, and it performs the back flow preventer operation well, keeping the bugs out but the air has to make such an immediate 180 in such a small space.  Weigh the benefits against the extra time the dryer will likely run.  And always make a point to periodically inspect any termination for lint accumulation and sufficient air movement.