G70 Forged Alloy Steel or G43 Forged Carbon Steel in Selfcolor, Normaly Attached To The Master Link or to The End of Chains, or Joined to Grab Hook in Transportation. Quick Search:  clevis hookgrab hookshortening hook
Details:
G43 forged carbon steel
G70 forged alloy steel
Quenched and tempered
Ultimate load is 4 times working load limit by straight pull, 3 times by side pull