Comparison : Item # NH1637C100, 90º Flange Head Elbow for Inch-Size Tube
Item # NH1637D100, 90º Flange Head Elbow for Inch-Size Tube
Item # NH1637N100, 90º Flange Head Elbow for Inch-Size Tube
Item # NH1637S100, 90º Flange Head Elbow for Inch-Size Tube
Item # NH1637V100, 90º Flange Head Elbow for Inch-Size Tube
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