This is a simple maternity belly ring barbell with a PTFE shaft. The adjustable length pregnancy barbell will allow you adjust the piercing to your size. The top bead size is 5mm. This navel ring measures 14 gauge and 20mm- 13/16 of an inch. Entire piece is nickel free. PTFE is a material that is non-allergenic, flexible, non-magnetic, invisible to x-ray machinery, and autoclave safe.