2a all ends thread class 28 2nd end thread quantity per inch w/two slots, 0.094 in. w by 0.141 in.deep, located in 1/2 in.tube end, spaced 90 deg apart un 2nd end thread series
3a 2nd end thread class do not dupe to other nsn; designed for unique application on: M981, M901, and M901A1 t.o.w. vehicle; hex size designed for confined clearance in the box of a hydraulic hand control assy; between a hydraulic line unjf 2nd end thread series
