There are a number of suitable jewellry types for anti-tragus piercings including curved barbells, BCR, CBB and segment rings. We stock a lot of these in micro gauges for people with smaller piercing requirement. In most cases the anti-tragus piercing is a 1.2mm gauge(thickness) although sometimes ever a 1.6mm can be used depending on the shape of the ear.
Healing times on this piercing could be reduced if you use a curved barbell made from Titanium or Bioplast/Bioflex. These curved bars do not move around as much as rings so will not aggravate to new piercing as much.
Bar length or internal diameter of the ring will depend on the thickness of the ear, check out our sizing guide. 6mm and 8mm for curved bars, and 10mm internal diameter for rings and horseshoes are the most common jewellery sizes suitable for the anti tragus.