Titanium Ball closure rings.
Titanium is a good metal if you react to various other metals. 
These rings are available in different thicknesses and diameters. You will need to know the size of your piercing to ensure you order the correct size. For hygiene reasons, returns and exchanges are not accepted on any body jewellery. This does not affect your statutory rights.
The thickness will range from a 1mm - 1.6mm. The diameter will range from a 6mm - 16mm. 
Rings are Sold Individually.
There are various colours to choose between.