I am unable to determine the material as this was not made by me. It has a color similar to antique-finished brass. The darkening is less pronounced than in the images. Also, there are individual differences in the darkening. Please inquire before purchasing if you are concerned. If there are no specific requests, I will send you my choice. Please refer to the scale in the images for the size. The background grid is also 1cm x 1cm. Other conchos are also on sale → #concho1942el This is an easy custom modification: simply make a hole in your wallet (leather wallet), bag, belt, etc., pass the screw through from the back, and tighten. You can think of it as a sturdy badge. You can use it in various ways depending on your ideas.