Sturdy MFG Co. SturdyONE Airflow Pin Set Sturdy MFG Co. brings to you the airflow pin set that covers the more nuanced airflow options that don't come included with the SturdyONE RBA. This set comes with three airflow pins in 1.2mm, 1.5mm and 4.0mm. If your airflow preferences are outside the box, or if you want to make sure you have every possible airflow option on hand, snag this set for SturdyONE RBA! Includes: 1x 1.2mm AF Pin1x 1.5mm AF Pin1x 4.0mm AF Pin