These are Heavy duty Eye Bolts used on very Large Chandeliers or pendants . The Iron one made in USA can hold at least 1000 pounds . We used these for the very Large Chandeliers we made in the past .  The Brass one is 3" diameter and has 3/4" threads .  The Iron one looks like 7/8" standard pipe threads . Selling them together as a mixed pair . They are very expensive .