Kuno piercings are foreskin piercings, which is why this option is only available to uncircumcised men. They can be placed through any point of the top rim of the foreskin.
Jewelry options for kuno piercings are typically limited to rings, although there can be a lot of variety within the broad category of rings. You can choose from captive bead rings, segment rings and seamless rings in a variety of styles.