[Metal Grommet Size] --- Inside diameter: 5 MM (0.2 Inch), outside diameter: 9 MM (0.32 Inch), length is 3.6 mm (0.14 inch) [Wide Usage] --- The easy-to-use grommet kit is suitable for shoes, clothing, shoelaces, DIY crafts projects, tarps, awnings, and leather crafts and adding ornament to your crafts etc. [Easy Storage] --- All 400 grommets sets and tools can be put in storage box with removable baffle to separate these compartments, which is convenient to find the corresponding components The structure is firm.Rustproof , performance is good, Color chips does not off. Installation steps: 1.Making a hole with a punch tool. 2.Put the back of eyelet through a hole from a front of clothes and a washer on the back of eyelet from a back of clothes. 3.Face eyelet to the base and wear on the base. 4.Push the install rod on washer and hammer the grommet together We don't recommend to use these grommets for thick fabric (such as wool blankets). the thickness of leather does not exceed 6 OZ. fabrics,mesh ,knitted fabrics, stretch fabrics and fabrics with wear on the should be lined on the back to prevent them from breaking away and tearing the fabric Note: Please keep them away from children to avoid choking. Color: silver + black + green bronze + gold material: metal Package Contents: 400 * Grommets (4 colors and 100 sets each color ) 3 * Tools 1 * Storage box Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.