This pair of BLUE Eyeball marbles measures approximately 21mm or almost 7/8" in size. Each marble is handmade of solid glass. you wont be able to stop staring at these beauties.... and they wont stop staring back. The stock photos are a representation of what you will receive, each marble is unique and will vary slightly from photos. due to the way these marbles are made, they are not perfectly round and often have minor imperfections. fun for collectors or craft projects.