This piece mounts on top of the valve; mounted to this is the handwheel and gearbox assembly (mfgr calls it base assembly), then actuator mounted on top of these two items
NSN 6645-00-139-9239
NSN 6150-01-327-4562
NSN 5915-01-373-1708
NSN 5855-00-879-7245
NSN 6150-01-420-9551
NSN 6220-00-892-7755
NSN 5945-01-294-9351
NSN 6150-01-617-0145
NSN 6150-00-968-3700
NSN 6650-00-578-6543
NSN 5975-00-173-1810
NSN 6320-01-544-6447