3/16" (about 5mm) antique brass plated steel eyelets. Designed for leather working. Antiqued Brass is darker than raw brass and goes well with just about any color. 3/16" diameter eyelets are large and generally used for leather. Questions about setting eyelets? Check out the Riveting 101 link in the Related Products tab, or call our friendly sales staff at 1-800-366-2156, or email us.