This is a pack of 100 antiqued brass effect eyelets. They are used to reinforce holes in fabric and thin leather.
They have an internal diameter of 7.93mm (5/16") and the central tube section is 5mm deep.
These eyelets are suitable for use on leathers of up to 3mm thick.
To fit them, use the Ivan brand 5/16" eyelet tool, as seen below in related items.
Fitting Details:
These are one piece eyelets, so the process of fitting them to your leather actually forms the reverse side of the eyelet, by folding the central tube of the eyelet around the edge of your leather.
Once you’ve punched holes that your eyelet centres fit into snugly, (It’s important that there is no slack around the hole) push your eyelet in from the front face of your leather, lie it face down onto the fitting tool base, and put the upright punch tool into the eyelet central tube section.
When you hammer this, the shape of the fitting tool will bend the eyelet tube down over the reverse side of your leather (which is currently facing upwards) to complete the fitting process.