It is a 6 mm capsule known as a bird's eye in the market. These eyelets (Capsules) are generally used for ventilation holes of hats, shoes, tents, textile and leather products. Our 6 mm eyelets are treated with durable coating for rust-proof and moisture-exposed products. Outer Diameter: 10mm Inner Diameter: 6 mm - 15/64" Product Price is Valid for 1 Package 1 Package: Contains 250 products.