3b 2nd end thread class flange welded to adapter; boss per MS33649 2 places perpendicular to ea other; adapts check valves to pneumatic components test stand; u/o B1b acft unj 2nd end thread series
2a 1st end thread class 6 2nd end bolt hole quantity 16 1st end thread quantity per inch one hole offset, flange hexed between 4 holes un 1st end thread series
2a 1st end thread class 7 2nd end bolt hole quantity 16 1st end thread quantity per inch one hole offset flange hexed between 5 holes anodize surface treated un 1st end thread series
2a 1st end thread class 7 2nd end bolt hole quantity 16 1st end thread quantity per inch one hole offset, flange hexed between 5 bolt holes un 1st end thread series