Used these to make a plexiglass distribution box to convert one of my 6 dust collection trunk lines to two 4 lines. The exterior stepdown creates a solid stop against the holes I drilled in the plexi. No expensive pvc 6-4 wye fittings needed. Note that distribution box doesn't maintain flow as well as fittings would, but I've got short runs and 1900cfm to play with, so worth the sacrifice in suction. Wouldn't mind if it was a little stronger (thicker walled) of a fittinf, but that would decrease the interior cross sectional area and reduce flow. Works great.
Rating:
[4 of 5 Stars!]