This Cowboy Boot charm is gold filled with a flat, open back.  .59x.74 inches in size.  Small and light weight. A 4MM gold filled jump ring is included.

Gold Filled charms are one step down from solid gold, and they are highly durable and won't tarnish.

If matching gold colors matters to you, be sure to check the description of the item you are buying to see if it's the same color.  Gold filled 14KT and 18KT are different shades of gold, with 14KT being brighter and 18KT being darker.