We recommend 16g 5/16" curved barbells for anti-tragus piercings. At Metal Illness we offer three-size ball ends ranging from 2mm-4mm. If your piercing is fully healed and you would like a snug fit we recommend sizing up or down based on your desired look. Depending on the thickness of your skin and placement you may need to size up or down. If you are unsure what you need shoot us an email at god@metalillness.com. We are happy to help!