Coin Slot Piercings
A "Coin Slot" is simply an extended piercing hole, where common piercing sizes range between 18g (1mm) to 12g (2mm). A coin slot is normally a 12g width minimum by 6g (4mm) minimum long.
This allows all the wonderful stacking of rings to happen.
Coin slot piercings can be super cute and dainty, or they can be loud and proudly bold. This really comes down to personal style and preference on both the size and shape of the slot, and the jewellery that is fitted after the healing process.