These are just your basic round ring, made of steel, but brass plated so they’re shiny gold in color. About 1-3/4″ in outside diameter, 1-1/2″ inside dia. 
The ring metal is about 1/8″ in diameter. Non-welded, so you can bend them open/closed if you’re so inclined.  Pack of 10 for $8.00, USA shipping included. RNG-123