Titanium is one of the best materials for body piercings, that's why this belly ring with a titanium barbell and acrylic balls is a fabulous option. 

Titanium doesn't contain any nickel particles, so allergic people or people with piercings that aren't fully healed can use it. 

This barbell has the standard length of 3/8" (10 mm), but you can also select a shorter model if this one doesn't fit your piercing. Besides, you can also choose the diameter of the balls you prefer. 

You can also find the same model of belly button ring with a surgical steel barbell, which is a bit less expensive.