SWIVEL CONNECTION, really a Shim Sickle 6" Long on an 842 New Holland Forage Harvester or Silage Chopper.
New Holland: (842) - NH 2 ROW CROP UNIT (7/60-12/69)
(This part listed as SWIVEL CONNECTION, really a shim Item # 17. Related P/N's 37529, 38549, 38550.) This may fit other applications.