2-1/2'' Elbow Dust Collection Fitting

• 2-1/2'' O.D. Black plastic elbow for Dust Collection
• 2-1/4'' I.D.

For best airflow, consider using two 45 degree elbows in place of this 90. I guess molding plastic in the shape of a bent tube is difficult, because this elbow has an obstruction inside instead of a smooth curve. Imagine a corner formed by two straight tubes mitered on the ends and joined like a picture frame: the inside corner is square. That's the contour inside this elbow. Since the outside is round as you'd expect, the square inside corner constricts airflow.