1,These keyrings are made of iron,durable and strong. Flat design can keep your keys not slip off from keyrings. This kit includes: 15 pieces of 0.78″ / 20mm flat keyrings,15 pieces of 1″ / 25mm flat keyrings,10 pieces of 1.18″ / 30mm flat keyrings,10 pieces of 1.3″ / 33mm flat keyrings,and 10 pieces of 1.5″ / 38mm flat keyrings.