Product review (2 stars): Will leak air and lint through openings in "wall exhaust ...
Will leak air and lint through openings in "wall exhaust connection" to rectangular vent body and at extension connection.  A/C tape did not stop leaks.
Consider "Rt. Elbow 3" male to female -- connected aluminum to flex vent with 3" Water Pump"  clamp (adjusted by nut w/ track)-- connected to well manufactured external wall vent/flap by again with a 3" Water Pump" clamp .  This worked for us.  No leaks...